My 1995 855T has 'good' brakes. But every once in a while I will get a light shudder when stopping from 55mph. When I removed the red glue from the pads and the caliper piston, the front brakes started to behave much better, and have been getting better each year(3).

I noticed that when I apply the brakes lightly while backing down the driveway, the car turns to the right - right front might be grabbing more than the left.

But, when I start going forward on level pavement, it does the opposite! Slight drag to the left with the brake lightly applied.

Is this a caliper problem? A pad problem? A rotor problem? An alignment problem? Bad control arm bushings?

I am looking for input, not a fix. This car is about to go on blocks for the winter. It is starting to get too cold in the garage.

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Keeping it running is better than buying new

Not being an expert on the FWD Volvo's take my advice with a grain of salt.

We noticed some of the behaviors you mentioned on our Saturn race car in the wet many years ago and it caused us to actually go through the all of the mechanicals that affected the guidance of the wheels under braking load. Three things became apparent:

All the bushings in the suspension were completely shot (this is budget racing) but the ones on the driver side had become oval while the passenger side were just soft, cracked, etc.

Springs left to right did NOT have the same free length or sag.

The driver side strut appeared to have considerably less compression damping in the "soft" initial part of the stroke.

How does the apply to your situation? If neither caliper is binding (piston seals still retract the pistons and slide pins still slide) you are looking at differential wear of items that affect Ackermann steering but also squat under braking. These are usually only the bushings at the suspension and steering mounting points. Lower a-arm bushings worn oval will change toe with less force as well (they are designed to change toe, but if the drivers side does more easily...).

Likely, you are looking at soft parts or calipers or a combination of both.

This is NOT a daily driver, just a project car that almost went to the junk yard. When I drove it home, there were no brakes. Both rear caliper pistons were were glued to the outside pads. New rear rotors, calipers, and rotors, along with freeing up the front pads and cleaning up the slide pins allowed me to drive the car. The braking got better after a few quiet road 60-0 stops. Not up to Volvo standards, but better than typical American cars.

The slide pins, all 4 of them were cleaned of crud, there were no dust covers on them. I am wondering if the area where the slide pins slide is crudded up.

When I removed the pads, the pistons retracted easily enough.

The struts and shocks, who knows how old they are, seem to work. There is absolutely no nose dive even in a panic stop, and the car corners flat. Not bad for 181K miles and 25 years. But it rides a little rough below 40mph, great on the highway! Due to rust and peeling paint, I have no idea who made the struts.

Yes, the bushings could be getting old. The rear suspension clunks, I am just not looking forward to replacing them - special Volvo tool. And the rusty bolts.

Like I said, this is a project car waiting for the 850 to go up in value. I also joust with windmills.



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Keeping it running is better than buying new

I know, this is a Klaus brain teaser.......

In both cases it’s the LH caliper grabbing. Think about it - you’re rolling backward, apply the brakes, and the LH caliper grabs. That causes the LH wheel to thrust forward, which translates to the wheel arcing inward due to the steering geometry (so car turns right). Apply the brake while moving forward and the LH wheel thrusts aft which causes the opposite reaction.

But is it a case of the LH being too grabby or is the RH sticking in the bore and not wanting to apply pressure to the pads if the foot pressure is light. Jacking up the wheels and having an assistant apply light foot pressure while you spin each wheel should answer that question. How are the pads wearing?
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

LOL to your purple calipers!

What you describe in how the brakes work brought back a long forgotten memory.

If you lock the front wheels in a panic, and turn the wheels to the left, the car will pull to the right. Also works the other way. I tried this in my 1964 VW and blew the mind of my doubting passenger. And it also explains a lot of accidents where people try to avoid hitting something to no avail.

This is why I love ABS.
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Keeping it running is better than buying new

Good answer! It will be most difficult to determine which caliper is off, keeping the exact pressure on the brakes while turning the front wheels might take 3 people. 2 to turn the wheels and one to apply the brakes. Or... put the car in gear and see which wheel stops first??? I am talking about very light pressure.

I don't have a micrometer to check the pad thickness or the rotor thickness. I should probably trash the pads and rotors and replace them with Ate quality parts. The calipers do work because a hard stop does not pull the steering wheel, and the car does track straight on a level road.

I don't mind getting remaned calipers, but if it is not necessary why do it? If I get new calipers, should I paint them yellow or red???? LOL
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Keeping it running is better than buying new

"... If I get new calipers, should I paint them yellow or red????..."

I'm kinda partial to these:

http://i.kinja-img.com/gawker-media/image/upload/s--2LeYCmzb--/18s0fj4r24h2pjpg.jpg
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)