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Hi all,
Once again, trying to help diagnose my son's '83 245, which is 150 miles away.
He has a stiff brake pedal when the engine is off, but once he starts the car, the pedal goes almost completely away. Brake fluid is full, doesn't seem to be leaking.
I searched the archives, but the ones with a similar situation had just replaced a brake component. No brake work has been done recently on this car.
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Had similar symptoms occurring in my '91 last year. I bled the master cylinder into itself (with MC installed and using the brake pedal) and since then the brakes have been spot on.
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Bleed the MC into itself. I'll give this a try.
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Pull off the check valve if you can blow through it both ways its stuffed.
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I removed the check valve and it only passed air one way.
It sort of honked a little as I blew through it, but when I inhailed through it,
it was air tight.
I bought a DORMAN replacement check valve as a back up, but the one on the car seemed to
function as expected so I left the original on the car.
However the DORMAN valve had a mu less restricted air folw.
Any thoughts?
Thanks!
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"However the DORMAN valve had a mu less restricted air folw. Any thoughts?"
Could be the new valve has a much stronger spring I guess. Had never dismantled any check valve before. As long as any valve allows one way flow it can be used.
The check valve is to reserve booster vacuum in case the engine died off during driving so that you still have assisted braking to stop.
Regards,
Amarin.
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Hi'
I have this same problem.
1990 volvo 240DL sedan, just replaced, front RT caliper, brake pads all around, Master Cylinder.
And now the pedal goes all the way to the floor with the car running, but has almost full brake pedal pressure when the car is not running.
I'll go try to test the brake booster using the method stated above.
I'm wondering what happened to the car in this thread.
It's great when people tell what it was that finally solved there problem.
Thanks!
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If you have the car running and foot on the brake pedal and turn off the ignition and the brake pedal rises up. The brake booster needs a rebuild.
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A brake booster rebuild is exactly what I was suspecting. OR possibly the brake booster check valve.
"If you have the car running and foot on the brake pedal and turn off the ignition and the brake pedal rises up. The brake booster needs a rebuild."
I tested the car running with foot on brake, the pedal being very soft, and turned the car off. The pedal did
nothing. However the pedal did regain a firm feel as soon as I pumped it.
There is probably a little air still in the system, but I'm 99% sure it's not causing the problem with the soft pedal.
Does anyone know how to tell if the booster, or just the check valve needs to be replaced???
Thanks
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No, you are describing a system that isn't bled of air. The remark about the pedal rising immediately on shutoff is describing an already high pedal rising just a bit more too quickly because the booster is leaking. Go back and answer the question I asked you.
--
Art Benstein near Baltimore
Those who jump off a Paris bridge are in Seine.
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Hey Art,
I appreciate your help.
I got a working caliper from a 240 at the junk yard.
It looks exactly like the one that was originally on there.
I'm selling this 240 sedan that I'm working on and replacing it with a newly acquired 245.
trying to get it running as cheaply as possible to sell. AND that's why I didn't just go buy a new or re-manufactured caliper.
Is that the question you wanted me to answer?
Thanks again for your help.
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That helps, but truly does not answer it. We have, on this board, helped many folks identify mistakenly rebuilt calipers, so it would be a reasonable troubleshooting step to first find out if you, too, were aware of this, and understood the concept behind it.
It would help us help you if you included the whole story, which I'm sure you would if it wasn't so convenient to link your symptoms to the OP's -- who surely did not return the favor of help given him by revisiting and concluding this thread. But that's par.
Still, in my mind, without hearing the whole story behind your troubles, i.e. the reason you replaced one caliper and one master, it sounds to me like you are having trouble getting the air out. And this is because you found a fairly shiny one at the junkyard which another unfortunately unaware owner could not bleed. Just a guess, but we'll never know, I'm sure, unless you tell us.
"It looks exactly like the one that was originally on there."
How about the dimples?
--
Art Benstein near Baltimore
Your continuing acquisition of wisdom outpaces the absolute value of my mental decline. -- Anonymous
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Once again your reply has exceeded my expectations!
How about the dimples?
Honestly I'm not sure what you mean by dimples.
I'll go look if I just knew what feature of the calipers is called the dimple.
Although I have just about run out of time to work on this car today and will have to get back into it in a day or two.
Thanks again!
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Ok, the light is on now and someone is home.
I did a little research at turbobricks.com and went out and looked at an old GIRLING caliper, and now I get it about the "dimple" thing.
I don't have time to get under the sedan right now, but will report back tomorrow.
Thanks again!
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I gave you a link in my other response, but you must have missed it. Just search "caliper dimples". Maybe fill us in on the details of what you are doing. There is some misinformation in this thread belonging to montysano.
--
Art Benstein near Baltimore
When an actress saw her first strands of gray hair she thought she'd dye.
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Have you done any checking to see whether the new caliper you installed was remanufactured correctly? Dimples match?
--
Art Benstein near Baltimore
When you've seen one shopping center you've seen a mall.
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I have not had a chance to check the caliper in question for dimple alignment.
I had to work and will check it tomorrow before I go to my other job.
I'll report back asap.
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Alright.
The JY caliper that I put on the RT Front does have both dimples on the same side!
I was able to bleed the MC back into itself, and this helped the pedal regain some firmness "when the car is Not running". As soon as I turn it over, the pedal becomes as floppy and soft as can be.
I'm really feeling like this issue is going to turn out to be brake booster OR the check valve.
I'm not hearing a "hiss" now. But I used to hear a "woosh" sometimes when stopping and thought it was a Volvo thing, since this 240 was my first Volvo.
When the car is running and I pump the brake, sometimes the idle drops in RPMs a little, and quickly returns to normal after a few seconds.
I will consult FAQ regarding brake booster/check valve diagnosis, however any clues or wisdom would certainly be welcome!!!
Thanks!
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"I was able to bleed the MC back into itself, and this helped the pedal regain some firmness "when the car is Not running". As soon as I turn it over, the pedal becomes as floppy and soft as can be."
Okay, assuming you got the air out of the MC, there may be springiness being introduced by the backing plates of the brake pads or the dust boots.
It has been found that the backing plates, if rusted or slightly warped, cause space between the piston and brake pad, which first must be transversed before the braking action against the rotor can begin ie. springiness. I don't use them.
Also during insertion of the brake pad, the dust boot rubber may get caught between the piston and brake pad, introducing sponginess.
Btw, I find bleeding the MC back into itself a waste of time. Brake fluid isn't that expensive and not much is required. Easier to just crack open the nuts at the MC, depress brake pedal and block it down, tighten nuts, let pedal up and check for firmness and repeat if necessary. (Use a rag to catch the expelled brake fluid and wash it off with water so it doesn't eat the paint.) Basically you are expelling the air with the nuts cracked open and inputting fresh fluid from the reservoir with the nuts tightened. Quick and easy.
--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.
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OK, you've eliminated the usual cause of failure to bleed a "new" caliper on the front. This is the first step.
Since "floppy" and "firm" are subjective experiences (ahem) it could be true that suddenly just as you decide to replace a caliper and master the brake booster gains spectacular ability to assist the pedal. Keep in mind that is all it does.
If you have air in the system, your concept of firm, with the brake assist missing, may not include effective braking. Your leg doesn't have the muscle memory needed to compare an effective firm pedal to one that feels firm sitting still, pushing on it with the same effort you'd use WITH the power assist, but is actually soft when called upon to stop the moving car. Air.
Given bench bleeding the master was new to you, I suspect getting the air out of your system will be the true goal you seek here. Go back to the beginning; what was it that motivated you to replace the caliper? The master? I won't ask again. Promise.
--
Art Benstein near Baltimore
No trees were harmed in the posting of this message...however an extraordinarily large number of electrons were horribly inconvenienced.
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Art, Thanks for all of the sage advice... The 1990 244 in this post sat for a good 2 months after much effort was expended trying to find the cause of the "soft" brake pedal. It included multiple attempts to bleed the system as well as other suggestions you and others gave me.
After sitting for 2 months while I drove the 1993 245 I picked up, one day I decided to dig in and recommit to fixing the brakes on the 244 so I could sell it. Low and behold!!!! The brake pedal had become firm under normal foot pressure and functioned perfectly when I test drove the 244.
A month later after some detailing I sold the 244 for $900 to a BMW mechanic.
I have noticed that many of these posts have no closure and DIYers looking for answers are often left wondering "what happened..." In this case I think that some bubbles in the brake lines must have floated up and out of the brake lines over the 2 months that the car sat.
Art THANK YOU and the rest of you guys who share and contribute to these pages!
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The thing that motivated me to replace the MC was the brake pedal would continue to slowly fade towards the floor even after the car would come to a stop. So after a little investigation on several Volvo forums I concluded that I should install a remanufactured MC.
I was hoping that the MC would cure the pedal problem and I could then sell my sedan in good conscience and concentrate on my newly acquired 1993 245! The saga continues...
After I installed the MC and was bleeding the system, I broke the outside Front Rt bleeder valveI on said caliper, subsequently I found that the 2 upper pistons in the Front Rt caliper were seized. I read mixed opinions regarding bench bleeding, and since I don't have a vice available, decided to chance it without the bench bleed. After installation of the MC I bled it into itself. Is there any difference between a bench bleed, and bleeding the MC into itself after it's installed?
So I have SLOWLY driven the car around the neighborhood at night with one hand on the E-Brake.
It barley stops with pumping, unless I'm going up hill. It also pulls to the left a little. AH HA!
I'm now suspecting that a brake hose or line to the Front Rt caliper may have been blocked and is creating an air pocket in the brake system.
BTW if you can't tell this is my first attempt at a brake job. :-p
And after reading some other comments, I suspect that my assistant my have killed the MC I put in because I didn't know at the time to put a block under the pedal to keep it from going to the floor.
Whew...
I hope that anyone who reads this may get some educational value of what NOT to do, or at least good chuckle.
I continue to send much gratitude out to those who have been participating in my education.
Thanks!!!
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"It barley stops with pumping"
It still sounds like you have air in the MC.
Keep in mind that when you bench bleed (or bleed the fluid back into the reservoir), you are still likely to introduce air as you remove tubes and attach brake lines. Thus my previous comment about bleeding the MC.
--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.
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Nothing here to chuckle about unless you're reading my sig lines.
The rules are much more effective when you know the reasoning behind them. The "bench bleeding" is a rule because getting the air out of the master is necessary. It takes many strokes. You don't want to push that air into the pipes and the rest of the system, and you don't want to waste a lot of fresh brake fluid, so you bleed it "into itself" and it matters not whether it is mounted to your booster or clamped in a vise.
The rule about not pushing the pedal to the floor is for a used master. There's no problem doing this with a new one. Probably 90% of the DIY new ones are new, because someone pushed the pedal too far on the old one. The reasoning behind the rule is that the unused surface of the master cylinder is rusted by old contaminated brake fluid, so when the seals of the pistons are pushed over that rough surface, they no longer effectively seal.
Without your saying it, I assume the pedal was effective before you decided to replace the master -- the only problem being the slow bypass failed seals present when, say, sitting at a stoplight. Guessing the caliper replacement was a byproduct of the master replacement's bleeding attempt, rather than the other way around.
My opinion about brake work is we have no business cutting corners to save money. It is a false economy. Getting help to bleed Volvo dual/diagonal systems will damage the relationship with your helper. Doing it alone requires expensive pressure bleeding equipment. Everywhere you look on a 20 or 30-year-old neglected car, you have parts failing. Education costs money.
--
Art Benstein near Baltimore
"I employed some imagination here where memory fails." -kittysgreyvolvo
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Everything Art said. To add to these, even "veteran" 240 owners often take 2-3 tries to get the brakes bled successfully after a caliper replacement.
Best investment I ever made was a homemade pressure bleeder. Assistants are unreliable and I need to work things like this at odd hours. I spent about $12 on mine and it save me hours of work on the Volvo. Instead of following the bleeding proceedure, I can bleed both rears and then each fron caliper without running around the car. Still, for good measure I do two round of bleeding...one until clear, Pilsner (just got Stout colored fluid out of my work truck!) colored fluid comes out with no bubbles and one more to make sure there still are no bubbles.
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To piggyback on what Art is implying...did you do two successful rounds of bleeding on all 10 bleeders? If not, are you using a pressure bleeder and only doing one round on all 10?
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Any chance someone pushed the pedal all the way to the floor during the bleeding process. I had a friend assist me bleeding my brakes once, when we were younger and dumber, and he smoked my master cylinder this way. Then after having replaced said master cylinder we could not get proper pedal no matter how long we sat there in the freezing cold and dark bleeding the dam system. It was then I resorted to this web site and maybe it was Art or Lucid or some other volvo guru who told me I needed to bench bleed my master cylinder.
Anyways, two things I learned way back then. Never put the brake pedal to the floor whilst bleeding and always bleed the master cylinder back unto itself. Sounds like a pain in the arse but believe me it is better than sitting there with a friend who would rather be drinking saying,"push, hold, release", a million times.
Also, what Art is saying is 100 percent correct. We thought we had pedal but when the car was turned on the pedal went down too quick. I suspected the booster and the check valve as well, but trust me those were not it. I would focus on air in the lines for sure.
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Do not use the brake pedal (and master cylinder) to push out brake fluid to bleed the brakes. A great way to ruin new and rebuilt brake master cylinders should you press too hard on the pedal, driving the cylinder too far forward.
If you must perform a brake bleed using th brake pedal, many threads exist that describing placing sections of wood. IIRC, you use I believe two pieces of 2" x 4" lumber under the brake pedal, to limit brake pedal travel, while you have enough brake pedal travel to push out enough fluid as your brake bleed assistant very carefully open (unscrew-loosen) and close (tighten) the bleeder nipple.
At brake pedal release, with a unidirectional valve brake bleeder hose at the nipple, or using an assistant with a wrench to very carefully open and close the bleeder nipple, air can re-enter the caliper through the thread interface.
Rent or use a power pressure brake bleeder kit, like the Motiv power brake fluid bleeder. Verify the pressure brake bleeder is used for the glycol (up to DOT 4) or silicon (DOT 5) brake fluid. The two types of brake fluid do not intermix. You can mix DOT 3, 4, and 5.1 brake fluids as these fluids are glycol based. Yet best to use one kind of DOT fluid.
Use a 91% isopropyl alcohol, or the like to clean the power pressurized brake bleed throughly of glycol based fluid, if it is not clean to begin with. Let dry. May also want the power pressurized brake bleeder, reservoir and pump (run alcohol through the brake fluid piping and pump assembly) before you return it to your friend or the rental tools store.
Always replace the fluid every two year, optimally, or as the brake fluid darkens in the fluid reservoir to a dark tan, yet still clear.
Allowing the brake fluid to turn black in the fluid can cause you and your Volvo to run the risk of caliper piston seizure, premature master cylinder failure, and problems with the brake check valve.
Glycol-based brake fluid (DOT 3, 4, & 5.1 [not silicon fluid DOT 5]) is anhydrous, and attracts moisture, usually through the hole in the brake fluid cap. The hole must remain clear, however.
As glycol-based brake fluid collect water, the brake fluid become acidic, fomenting corrosion inside the brake system, certainly the various metal channels like metal brake line, check valve, and calipers. Also, water moisture exposure alone foments corrosion of metal brake parts inside glycol-based brake fluid systems.
If you mean to perform a brake bleed to replace so described aged, black brake fluid, you may want to perform a first brake fluid flush, so that clean brake fluid comes out of the hole connected to the brake bleeder nipples. Use a clear soft vinyl or nylon hose. I think that that used for fish tank. I forget the diameter. Brake bleeder nipple sizes can vary if an OEM (Girling or ATE) caliper or a re-manufactured. Re-manufactured brake calipers may have a smaller barbed fitting on the brake bleeder nipple.
Replace the or press on the rubber boot over the brake bleeder nippled barb so stuff and moisture does not collect (too much) inside the open (exterior) side of the brake bleeding nipple.
If you purchase re-manufactured brake calipers, they may need to be painted as they usually come with not finish, as the Autozone reman front 240 Girling brake arrived.
And of course verify the dimple alignment on remans; already well treated in this thread and in other threads here on you mighty brickboard.com.
As even the last year of the 240 reaches 23 model years old, inspect the flexi brake line front and rear. Outer rubber severely cracked? Replace these flexi brake lines. And correspondingly, you may have to replace the copper alloy brake lines between the flexi rubber brake lines and caliper.
The copper alloy brake lines can swell, and removal may destroy them.
Just an FYI. As aforementioned by other posters in this thread, use a pressure power brake fluid bleeder tool like the Motiv brand power bleeder. Can probably borrow or rent.
Questions? Comments?
Hope that helps.
Sorry for teh expository. Damned dyslexia is a bother, and exercising (exorcising?) it away. Trying to.
Thanks,
Duffed Mac Dud. (Wanting symmetry.)
--
Jonathan Harshman Winters III: The Mightiest, Greatest, & Most Powerful Comedian & Comedic Actor North America in Perpetuity
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Odd that the pedal works with the engine off. This makes me suspect the brake booster.
If it were my car, I'd start by bleeding the brakes and checking for visible leaks through the whole car, but especially around the master cylinder/booster and also around the pedal itself.
Next, I'd double check the fluid level and mark it before starting the car (I use a grease pencil on the outside of a clear master cylinder reservoir whenever I do a brake job and fluid flush, a little line can tell volumes down the road...)
Now start the car and pump the brakes. Does the pedal stay "soft"? Do the brakes work well or do they fade out? Has the fluid level dropped after a few hard applications with car running?
If there's air in the system, the pedal should be bad, engine on or off. If the master cylinder is bad, the pedal should slowly drop, engine on or off. If the booster is bad, the pedal should work as though there were no or weak brake boost, but fluid may be getting pulled past the seals, causing the pedal to drop--this can show as a loss of fluid in the reservoir with repeated pressing and holding the brakes with the engine running.
Good luck.
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Hey Ben,
I'll vote with all you said.
Phil
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Hard to diagnose with 3rd hand info but I think you mean that the pedal goes to the floor with engine running. "Goes almost completely away" is a bit vague????
Is their any braking action at all?
If you let the brake fluid reservoir go completely empty your symptom could happen as that will allow air to enter the system, even if fluid is added the air is still there in the lines and will need to be bled.
If no leaks anywhere, and no one has worked on the brake system to introduce air, and fluid has remained topped up I would suspect a failed master cylinder.
--
David Hunter
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If there are no leaks and the pedal goes to the floor, the master cylinder seals are probably gone. The other possibility would be a lot of air in the system, but if you have not been working on the system that would be unlikely.
Does the brake failure light come on?
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Yes, the brake failure light has come and gone.
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You need to describe what almost completely away means.
Is he a new driver? It is suppose to be easier with the engine on.
Phil
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"You need to describe what almost completely away means."
No pedal. No brakes.
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To test the booster, press your foot on the pedal with the engine off, then switch on. The pedal should rise about half an inch.
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