85 Wheel Cylider Repacement / Leaking

[RageCage]

Hi,

There is brake fluid leaking out of my left rear wheel. I think it is the wheel cylinder leaking. The brake pedal is quite mushy. How much of a pita is it to replace a wheel cylinder? I have drum brakes, of course.

I'm going to go out now, jack up the car, and give it a look. I'm just posting this now, to get my question out there. I'll report back in a few hours what I find!

I remember the last time I tried to do work on the drum brakes. What a nightmare. If I have to remove those springs, I think I'll just take it to my trusty mechanic.

Can I get the wheel cylinder out without removing a lot of brake parts ?


How much labor would a mech charge to replace the wheel cylinder, assuming I brought him the part ?


Thanks

[inafogg]

yea the return springs need to be removed.i'd guess 1 - 1 1/2 hr. labor to install & bleed

[j cAT]

If you thought the replacement of the rear shoes was a pita, you need a pro to do this....this job may require,, a new backing plate as well as need brake lines in addition to the brake cylinder..

[RageCage]

inafogg, jcat,

Thanx. Yeah, I just got done looking at it. The horror / flashbacks came back to me. Tight springs. I'll take it to my mechanic. Hope all I need is the wheel cylinder. No leaks from outside, just inside. Pads were wet. Cleaned it all up, reassembled. Funny thing, brake fluid wasn't even a tad low, in reservoir.

[j cAT]

Originally Posted by RageCage

inafogg, jcat,

Thanx. Yeah, I just got done looking at it. The horror / flashbacks came back to me. Tight springs. I'll take it to my mechanic. Hope all I need is the wheel cylinder. No leaks from outside, just inside. Pads were wet. Cleaned it all up, reassembled. Funny thing, brake fluid wasn't even a tad low, in reservoir.

first off when you have a leak the reservoir must be dropping....is this the brake cylinder or the axle seal ???

I would check the rear diff level...

If the axle seal is leaking replace both seals and both axle bearings...

[RageCage]

Originally Posted by j cAT

first off when you have a leak the reservoir must be dropping....is this the brake cylinder or the axle seal ???

I would check the rear diff level...

If the axle seal is leaking replace both seals and both axle bearings...

JCat,

Good point. There was some wetness coming out of the diff housing, but it's always like that, and level doesn't drop. Must be slow leak.

But the axle near the wheel was dry. If the axle seal is shot, could it get diff fluid into the brakes ? I'll go out and check the diff level.

BTW, I was expecting to see drips of brake fluid coming off the wheel cylinder, but I didn't. Although there was plenty of fluid of some kind all over the shoes and the drum.

Thanks.

[j cAT]

Originally Posted by RageCage

Hi,

There is brake fluid leaking out of my left rear wheel. I think it is the wheel cylinder leaking. The brake pedal is quite mushy. How much of a pita is it to replace a wheel cylinder? I have drum brakes, of course.

I'm going to go out now, jack up the car, and give it a look. I'm just posting this now, to get my question out there. I'll report back in a few hours what I find!



I remember the last time I tried to do work on the drum brakes. What a nightmare. If I have to remove those springs, I think I'll just take it to my trusty mechanic.

Can I get the wheel cylinder out without removing a lot of brake parts ?


How much labor would a mech charge to replace the wheel cylinder, assuming I brought him the part ?


Thanks

the wheel cylinder only should be 1 hr labor for one wheel...
since you cleaned everything you should be able to locate leak...If its gear/diif oil it will smell and be heavy in viscosity...

brake fluid is like water,,,,also gear oil on shoes will cause them to grab usually...

[toddman67]

The reason for the level not going down in the master cyl resevoir is due to the proportioning valve. there needs to be presuure on both sides of the valve for the brakes to work properly. Once the rears started leaking the valve went into the protection mode giving you only front brakes. There's your spongee brake pedal.

[RageCage]

jcat, toddman67.

At this point, I think it must be brake fluid. I did not notice that pungent smell of gear oil, and the oil that was there on the shoes, etc, was very light. I was about to pump the brakes to get the leak to start, but then thought I might end up with the shoes stuck in the out position, and not then be able to get the drum back on !!! Probably the shoes would have just retracted with the pull from the springs, but I wasn't in the mood to take a chance.

The drip is coming from the inside of the wheel hub, down onto the inside of the tire.

[toddman67]

Clean everything good with brake cleaner, let dry and put the drums back on before trying to pump the brakes. Otherwise you will just blow the wheel cylinders apart. After you pump them remove the drums to find your leak.
If your shoes are contaminated? It would be better to get new ones.

[j cAT]

Originally Posted by RageCage

jcat, toddman67.

At this point, I think it must be brake fluid. I did not notice that pungent smell of gear oil, and the oil that was there on the shoes, etc, was very light. I was about to pump the brakes to get the leak to start, but then thought I might end up with the shoes stuck in the out position, and not then be able to get the drum back on !!! Probably the shoes would have just retracted with the pull from the springs, but I wasn't in the mood to take a chance.

The drip is coming from the inside of the wheel hub, down onto the inside of the tire.

you may require a brake line since that is also a bad area for lines to survive the winter elements...

with this much leaking you must see brake res. level dropping though....also you should get the red brake light to come on it the leak is large..

if its leaking at the rear wheel bearing seal it is the that seal..the brake cylinder leaks from the very top of the backing plate down on every thing...

this should not be that hard to determine....also do not operate brakes with the drum off....slide drum on work brakes then remove drum to look for leak,,,,also with an assistant bleed the brake cylinder...maybe the bleeder is leaking.....///

[RageCage]

OK, I think I've got the thing figured out, generally, thanks to the advice here. I went out today and got under the car, and saw that there was currently no dripping, and the hub was pretty dry (the fluid from before had dripped off / dispersed).

I started her up, in park, pumped the brakes 4 times, shut it off, got back under, and there was now some fluid dripping off the bottom of the hub. To me that says it's brake fluid as opposed to differential fluid. I still don't know why the brake fluid level is still full. A mystery.

Thanks for your patience. I appreciate the help.