Rear brakes lock up when going in reverse

[jseabolt]

I've got an odd problem with my 131. Whenever I back the car out of my garage (it's still under construction), the passenger side rear brake locks up. I could back up 4 feet or 10 feet then all of a sudden it locks up.

It doesn't lock up while going forward. If I floor the engine when the brake is locked up, it will break free and seems to be OK from there on until I park the car for a few days then it happens again.

I know I'm going to have to pull the drum off to see what's going on but I was just wanting some input if anyone has ever seen this happen.

I'm thinking one of the springs that holds the shoe in place is broke causing it to jam. When I am backing up, I'm not using the brakes. It just "happens".

If the parking brake was adjusted too tight would this cause an intermittant jamming?

I can lift the car off the ground and rotate the wheel forward and it never jams but can rotate it backwards and cause it to jam.

[djape1977]

beats me. jamming while hand - turning wheel in reverse?
i had same problem on my lada but it turned out to be faulty rear control arm. when going in reverse, rear axle would move a bit, causing a handbrake cable to pull on the brake.

[simon131]

The locking rear brakes are probably due to dodgy adjusters on the shoes. The 131 has 'automatic' self adjusters, but the reality is that they rarely work as they should and often need manual input to slacken then off. It's likely that the adjuster in one drum fouls when the wheeel is being rotated backwards and allows the shoe to move out onto the drum.

Could also be that you have a jamming piston one side or as you say the return spring is broken stopping the shoes from returning to their 'freed' position.

Slacken off the handbrake cable could also help.

Take a look inside the drum, should be easy to fix.

[jseabolt]

I have messed with the rear brakes on my other 131 I gave to my friend. The wheel cylinders were seized from sitting for so long. He says that car does that same thing as mine!

Could the self adjusters be removed and the rear brakes manually adjusted from time to time? Is that a smart thing to do?

I've messed with the four wheel drum brakes on my 68 Ford also. That car will stop on a dime. Even with manual drums.

But I have to syncronize the fronts about every 2000 miles otherwise the fronts don't grab evenly. 1968 was the last year Ford used drums on the front. I suspect the self adjusters are not working at all on that car.

[djape1977]

ford used front drums till '68??
jesus.....
that's whats wrong with us automotive industry.
i have a european ford 17m from 1970. and a friend of mine has one from 1966.  both have front discs.

why don't you just buy rear brake kit from yagmur? it can't be expensive. dunno 'bout the shipping fee but those parts aren't that heavy. excluding drums themselves ofcourse.

[jseabolt]

ford used front drums till '68??
jesus.....
that's whats wrong with us automotive industry.
i have a european ford 17m from 1970. and a friend of mine has one from 1966.? both have front discs.

why don't you just buy rear brake kit from yagmur? it can't be expensive. dunno 'bout the shipping fee but those parts aren't that heavy. excluding drums themselves ofcourse.

Yagmur. Never heard of it but I will Google it and check them out.

Some people over here in the US have transplanted the rear disc brakes from 124 Spiders onto 131s. Supposably they will fit but there are some hurdles. Something about the hubs on the axles not being compatible and the rear brake cables are not long enough or are too long. It's been done but I haven't actually looked to see why it wouldn't be a bolt on swap.

Concerning my 68 Ford: Well back in those days things like that were considered an "option".

Believe it or not, there is a "BRAKE" light indicator in the instrument cluster but there is no bulb or socket behind it! And there is no wiring going to the parking brake or brake fluid reservior.

On the Ford Fairlane in 1968, if you were willing to pay extra you could get air conditioning, P/S, P/B, front discs, 4 speaker AM/FM 8 track stereo, cruise control, intermittant wipers. On the Mercury version you could get power seats.

You could also get several different engine options. Ranging from the wimpy 6 cylinder up to the 427 cubic inch Cobra engine. Unlike US spec 131s which only came with twin cams. Starting with the 1800 and the 2000 cc engines. Mainly because it was cheaper to just federalize one engine for importation. I couldn't figure out why ever 131 I pulled up on Google outside the US had a 1600cc pushrod engine.

When I was in Britain my X 1/9 friend was bragging about the A/C on his Jeep Cherokee. About how nice it was to have A/C. I'm like, "HUH, it's July and the hottest I've seen it so far is 68F!" Why would you need A/C in Britain?  July in Britian feels like March here and July in Northern Scotland feels like November.

[sid131]

Yagmur is here he has all parts for 4 door 131s
http://131mirafiori.com/smf/index.php?topic=81.0

[djape1977]

sid beat me for a link to yagmur. thanks sid!
that 1600cc in other 131s is not a pushrod engine, its overhead cam as yours, just a single camshaft. lets say its a low budget 131. my 1982. 131 1600cl has SOHC 1585cc engine, 86hp and it has "made in brazil" on the engine block...
for rear discs conversion, easyest way is to get whole rear hubs with halfshafts, bearing, calipers and all from 124, 125 or 132 1800cc. then it's a simple swap over job. i have converted my 132 diesel rear brakes from drums to discs 10yrs ago and it was definately a big improvement. if i remember correctly, i had handbrake cable and rear brake hoses custom made which is no big deal around here and was cheaper than original fiat parts.
as far as my experience goes, all rwd fiats 1300/1500 series, 124, 125, 131, 132 1800 used same rear axle. diferent mounting points, brakes and diff ratios but same housing, halfshafts, bearings... 132 2000 and argenta have a diferent axle which is said to be much stronger and more reliable.

just for ilustration, here's axles from 132 1800 and 124

[djape1977]

sorry mate, you're wrong. only way i can find around that fact is that fiat maybe used diferent axle/diff/brakes combo for different markets.
what i wrote about rear axles is strictly from personal experience. only time i found halfshafts and bearings that weren't interchangable was when i worked on 124 sedan derivative - lada. but after 30 years of production, it's no wonder that russians decided to change wheel bearing size.
btw, my 131 has exactly the same rear axle as that top one on my photo, from 1975. 132 1800 special, except for panhard rod mounting point.

anyways... thanks fo opening my eyes to a fact that i might have fared better in life if i was a bookworm.

[jseabolt]

Two liter Spiders used the 132 series engine (stamped on the engine block). We didn't get any Fiats past 1982 so we didn't get the Argenta or 132 but it appears Fiat used the fuel injection system as well from the 132. Two liter Spiders used SEAT transmissions which are stamped on the side. So what sort of differential/axle did the Spider use? It's obviously not a 131 because of the trailing arm mounts.

Getting back to the self adjusting rear brakes. I got out my shop manual and low and behold if the 131 uses the same setup as the Yugo/128!! Why I didn't notice this several years ago I don't know.

I recycled the rear brakes from a low mileage parts car on my Yugo. Despite sitting for 15 years it had about 24,000 miles on them and the seals looked perfect.

I cleaned the bore out with fine sandpaper, cleaned everything with parafin/kerosene, greased the seals with o-ring lubricant and the brakes still work fine after five years. And they never jam while going in reverse.

I'm thinking it's either piece #5 or #6 that is sticking. Or the spring is broke.

[djape1977]

forget the position of trailing arm mounting points as well as shock absorber mounting points. they can be cut off or welded on where needed. no big deal.

never crossed my mind to compare rear brakes on yugo and on 131! but it did for front ones. you'll find that front brakes from yugo are the same as on 131 too.

[jseabolt]

I forgot I took a picture of this tool I made from an old screwdriver. It mimics the original Fiat brake tool.