hewboy! here i go again...has anyone converted their 122 to rear disk brakes? and if so, what's the best donor for the swap?

No big deal if your handy with a torch and have a 72/73 1800ES or a 140 diff. You will also need to change the front hubs to match the rear end bolt pattern.
I may be able to post more details on how to make the conversion but right now I'm up to my eyeballs in vintage Volvo ^*%$
Cheers,Jim

chas;

Please explain why you want to do this in the first place.

We've read all the discussions and seen all the arguments here before...

Some arguments which I can think of, and my comments to them:

They're easier to inspect and maintain! Probably the best argument FOR. Sure disc brakes are easier to inspect and maintain, but with anti-seize on the tapered axles, the drums are no sweat to get off once a year for inspection or work either....

Disc brakes are better! Fact is, that the fronts do most (~80%) of the work anyway...braking improvement (if ANY at all) is probably negligable, and the rear caliper pistons move so little, that in my experience, they often freeze in place anyway...like on my ES, 140, 740...so they we're contributing s**t to the braking for a long time anyway...and I didn't even notice! A better upgrade would be to upgrade to the dual-diagonal hydraulic system (leaving the rear drums, see recent Thread on the subject). You still get no better brake performance, but you do get additional safety of dual hydraulic systems.

I have too much time on my hands, I love to tinker, I got a free disc brake rear-end from my cousin Bjorn, and it has a ratio I wanted to try ...hey, have fun...and from your original question, that wouldn't seem to be the case either....also if you go ahead with the project, don't expect a big, or even noticable performance improvement for all your efforts.

...just wondering!

well justin, and the rest...thanx for the questions, because it made me ask why. well because my brakes suck! when i'm cruisin at 70 and a whitetail deer jumps out i want to stop NOW! i hate seein deer guts all over the freeway(and definitly would hate to see 'em all over my wagon!). i guess i've gotten too used to my late model vehicles with 90's technology brakes and these 35 year old brakes make me nervous. i'm getting used to leaving alot of room between me and the guy in front of me, but the way people drive they don't usually allow me that much space (there's always someone who has to be one more car ahead of someone even if it takes a shoe-horn to fit). so basically i'd like a little more stopping power.
thanx for the replys.

One other thing I thought of; the disk brake rears have a 27 spline Dana 30 differential. Much easier to find a limited slip unit if you so desire.
--
Justin 66 122E, 71 145S
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chas;

There's nothing inherently wrong with the design of your Amazon's 35 year old brakes!

Before you consider installing a dics brake rearend, you should assure that your brakes are in a decent state of operating condition...no frozen pistons up front, and a nice firm pedal and good feedback, as soon as the free travel is taken up (so well bled, and rear shoes adjusted)...if so, without the notorious vacuum assist unit, they will need a good bit of pedal pressure...certainly MORE than you may have gotten used to (or spoiled by) on modern, assisted or even power-brake cars. This should allow you to stand the car on its nose alright, although this will require a good stomp.

If however you want to decrease the braking effort required for the same amount of decel, you might consider a brake assist unit (and NOT the OE one)....and note that installing a disc brake rearend would NOT do this for you!!

It's brake inspection and possibly tuneup time!

Cheers

again thanx for the kick in the shorts, but i just re-read your post and your brake-assist has me goin' hmmmm? because that's exactly what i'd like, is to use less leg power; i'm scrawny! 5-7, 110lbs. man i don't have the leg of some 6-8, 240lb. Swede! you got any suggestions on an assist-unit? thanx again.

whew! you don't pull any punches do ya? you're right, as i said in an earlier post; i only recently acquired the wagon (3 weeks to be exact); oh she's been named "phyllis" after an aunt she reminds me of. but i DO need to crawl under there and take a better look at what i got; there's a spare set of pads in the spare tire well so that may be an indication of where to start. thanx for the kick in the pants, i needed it.

chas;

My intent is not necessarily to give you a "kick in the pants", just to straighten out your misimpression in no uncertain terms...disc rears are not going to improve your brakes, and by the way, problably neither is putting in those new pads you found in the tirewell!

My advice: Check out, adjust your brakes, and repair as required to bring them to a good original working condition...in the mean time, cut out the (right) leg press at the gym...your car will take its place!

Live with the car for a while...it'll probably grow on ya...ask anyone around here!...at least it wont pinch your cheek and give you a purple herbie, like the real Aunt Phyllis. If after a while, you still cant get happy with the brakes, post again...I think there are some Brickboarders around here who have installed assist units of other manufatuerers who can help you further (whimp!).

You might want to check out the SwEm site for more useful info/kicks in the pants/wise-a** comments etc. (www.intelab.com/swem)

Cheers

nice site...real nice site; makes me go hmmmm?

Hey Ron .....

Just to take some of the heat off Chas ..... Finally got the right set of shoes for the rear of my 65 .... HOWEVER .... took it to my Volvo Guru ... he removed the BIG nut on the end of the axle and installed the puller ..... cranked on a reasonable amount of pressure ..... NOTHING happened ..... applied The "hammer" all around the exterior of the axle taper ... still nada ..... applied the "blue tip wrench and thoroughly warmed the hub .... applied pressure ..... NADA ...... applied the "BFH" ..... with pressure from the puller ..... STILL NADA ..... declared a moritorium on the escalating warfare and decided to attack the OTHER side .... after the same procedures and same results I was amazed that the air had not taken on a blue appearance really got to give him credit for his amazing restraint ..... Anyhoooo .... brake shoes STILL have not been installed ... however he has left the axle bolts backed off about 1/2 a turn in the hopes that driving with them that way will start to loosen them back. We both are now beginning to wonder if when they were last installed that perhaps the key was not properly installed and has wedged in the hub ..... at this point any suggestions would be greatly appreciated ....

Gotta go pick up my head at the machine shop ..... CYA Later

PS Ron ... are you planning on making the VCOA Show in Vermont in October ??
--
Brett Sutherland & the 1.5 million mile 122 Canadian

The first time I took the rear drums off on my PV it had been parked for 15 years. After one of the rear brakes had stuck on and heated everything up. After being on the car for who knows how long. I rented one of the large, heavy pullers and put it on, spritzing the center with WD 40. Tapped it with a large hammer. Pounded it with a large hammer. Got an even larger hammer. Pounded harder and harder, cursed, sweated. Made not the slightest impression on the drum. Pounded as hard as I could with a very large hammer. Finally I felt as though something was going to pop in my head so I stomped off inside the house with the puller left on in it's final tightest position, had a beer, tried to relax, think about something else.

After about an hour and a half I heard a very loud BANG from outside. Went outside and the hub had jumped all the way off and was on the ground.

Using some anti-seize upon reassembly will make it easier to take apart in the future, but I wonder if it makes the joint a little less secure?

PS - I once put a 142E rear axle in my old '63 122 sedan (to replace the handgrenaded original rear end, apparently they need oil...) along with the 142E's radiator, engine, transmission, driveshaft, gas tank, seats, and rally gauge cluster. The braking didn't not improve at all. Neither was it worse, though, but the parking brake didn't work as well anymore.

John;

...this clearly proves that it takes beer to loosen drums!...if, for instance, you had been drinking a brewsky while you were working on the car, they would have come off immediately...apparently, you still need to learn about this important aspect of wrenching....

Seriously though, a slight film of anti-seize is not going to compromise the tapered axle to drum interface in any way...the taper assures concentric alignment (and a film of miniscule thickness is certainly not going to change that), and the key locks the two together for torque transfer. Besides, the tapered surfaces are precisely machined, but they are NOT a precision fit, which means that all but the slightest film of the AS will be displaced into the valleys next to any contacting peaks of the two surfaces, resulting in unchanged alignment between the two, but much improved, and as we know, a very desirable, release characteristics.

Brett;

If you have the luxury of time, leave the drum lubed (questionably effective), and (well) preloaded with the puller, and just let it sit for a while...it worked for John...and may for you. Heating the drum hub can only may help by introducing some thermal action...if that does give the desired release, just give the striking wrench another whack, go have a beer, and read the latest JK Rowling book!

Regarding the VCOA meet...unfortunately, I commited to another event well before I found out about the Vermont meet. I would have also enjoyed seeing old and new Volvofriends again, but unless something drastic happens, I dont expect I'll make it.

Cheers

Since about 80% of your braking is on the front wheels I'm not sure that
converting the rear brakes to disk is worthwhile, especially in terms of
stop/$. One thing I like about the rear drum brakes is that the parking
brake is really good. The parking brake on my 69 164 has never been able
to keep the car from rolling backwards. I've had it for almost 32 years now.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

There are a lot of 122s with disk brakes, but most are 67-69 and I don't know of any wagons. Most people just get a rear from a 70-73 1800. It will fit right up with the 67-69 122 bodies. Earlier bodies need custom work done on the trailing arms to make the late arms fit onto an early body. Or, you could do some work on the axle so the early 122 trailing arms would fit as is.

This may all me moot, however, as you have a wagon. You may be treading on relatively virgin ground doing this.
--
Justin 66 122E, 71 145S
Read vclassics!