dilemma!

[Dmcbrass]

A couple of weeks ago, I was backing up my 70 GT in a parking lot. I lightly touched the brakes and "bang", the rear brakes locked up. I thought I had backed into something. The problem became increasingly worse as I drove it back home. (11 miles) At one point the left rear wheel locked up and left black marks in the road. I talked to 2 individuals with extensive Opel experience that both told the same story. (Differential fluid leaking past the wheel bearing and on to the brake shoes.) I removed the drivers side brake drum, (took 3 days and lots of PB blaster). The brake shoes looked terrible (pretty chewed up). There was no end play in the axle. I removed the axle, and the bearing feels good. It actually feels like a new bearing full of grease. No end play and a firm feel when you rotate the outer race. The O ring looks OK, but I guess that must be where the fluid is coming from. I removed the right side drum and I had a small amount of end play in the axle. (I'd estimate less than a 1/16") I removed the axle and this bearing feels looser than the driver side bearing. It has a small amount of end play and the outer race turns freely. (more like an oiled bearing than one that is packed in grease). The car has had a whine in the differential ever since I installed the 73 rear axle, that I removed from my 73 parts car, two years ago. I've always believed that it was from pinion bearing wear as it is quite as a mouse when coasting and only whines when under power. Here's the dilemma. If the bearings cost $20 like they should I would replace the right one without giving it a thought. (Heck, I'd probably replace both of them.)
But at $85 a piece, I don't want to replace one untill it really needs it. What do you guys think? By the way, both bearings had a thin shim in the axle tube behind the bearing. The one on the passenger side had a ragged edge on the inner diameter of that shim.

[matl59]

I started reading your description of the problem and it sounded more like a bad brake hose to the rear axle. They swell with age and when you press the brakes fluid is forced through but it can't come back again locking your brakes up. Worn bearings and leaky seals sound like a secondary problem. Just my thoughts...

[azopelnut]

The same thing occured on my Ascona once. I replaced the wheel cylinders and it stopped

[hrcollinsjr]

If the brake hoses (plural) are original their time has come, replace them all. You didn't mention whether you found any fluid leaks unless I missed something. You have sealed bearings on the late model axle that you installed. There should be a smooth resistance when spinning them. Fluid can leak through the bearing or past the O-ring, I've seen both. One of them was on a freshly installed bearing that wasn't supported properly when it was pressed on. Thank goodness they weren't that expensive back then. I also went to a different shop for the next installation. It cost me a new set of shoes also.

The bearing that spins easily may very well be a part of your whine.

Harold

[GTJIM]

There should be no 1/16" movement in a wheel bearing - that one is Fubar and must be replaced. Your choice on the other one .... but do you want to pull it all apart AGAIN??

Replace rear brake hose (and the two front ones ASAP) plus do a proper job on the brakes shoes, drums and wheel cylinders - the lives of your nearest and dearest depend upon your brakes working!

The life you save ..... may be your own!

[hrcollinsjr]

Fubbar

Two B's?

Harold

[GTJIM]

Two B's? Harold

Harold - That is the polite form ... the Oriental form is Foo Bar.

[GTJIM]

By the way, both bearings had a thin shim in the axle tube behind the bearing. The one on the passenger side had a ragged edge on the inner diameter of that shim.

Those shims are extremely important, they hold the outer race of the wheel bearing from spinning inthe housing and damaging the mounting surface. It is important that new rear wheel bearings are correctly installed. See the Factory Service Manual for proceedure.

See: http://www.opelgt.com/forums/4c-axle...ring#post22187

[tekenaar]

Two B's?

Harold

. . . fibber?!!

[Rionart]

I have had the exact same scenario with a broken spring between the brake shoes, but that would have been obvious when you took the drums off....

[tekenaar]

I have had the exact same scenario with a broken spring between the brake shoes, but that would have been obvious when you took the drums off....

Same here on my Kadett rear brakes, but with broken brake shoe retainer twist pin and one of the spring cups became wedged between shoe and drum . . .

BTW, replacement brake retainer spring assemblies available in US are all too large and springs are too long . . . checked all available at the time, about 6 months ago. Another set of pieces (2 sets on each side of rear axle) to salvage before junking cars!

[Dmcbrass]

Still troubleshooting the situation. I've decided to replace the passenger side wheel bearing. It definately has too much internal clearance and as GTJim said, I don't want to be redoing this job in a couple of months. I've had brake hoses fail before and I'm confident that that isn't what happened here. This wasn't a question of the brake remaining locked up after I let up on the peddle. This was a case of one or maybe both rear wheels locking with only light brake pressure. The shoes are obviously saturated with either brake fluid or differential fluid. I'll give it the old "nose" test when I get home tonight. I don't remember smelling differential fluid until I removed an axle, so I've just about convinced myself that I'm dealing with a leaking wheel cylinder or two. Both were replaced in 2004 but may have been damaged when someone (I don't know who) drove the car with the emergency brake partly on. (That same driver couldn't understand why the car seemed to lack power and why there was smoke coming out of the right rear wheel for 15 minutes after the car was parked) The odd thing about that is, that I drove the car for several months after the incident and haven't needed to add brake fluid. It seems like if the cylinders were leaking bad enough to cause this problem, I'd be using fluid.

[OpelJim]

Still troubleshooting the situation. I've decided to replace the passenger side wheel bearing. It definately has too much internal clearance and as GTJim said, I don't want to be redoing this job in a couple of months. I've had brake hoses fail before and I'm confident that that isn't what happened here. This wasn't a question of the brake remaining locked up after I let up on the peddle. This was a case of one or maybe both rear wheels locking with only light brake pressure. The shoes are obviously saturated with either brake fluid or differential fluid. I'll give it the old "nose" test when I get home tonight. I don't remember smelling differential fluid until I removed an axle, so I've just about convinced myself that I'm dealing with a leaking wheel cylinder or two. Both were replaced in 2004 but may have been damaged when someone (I don't know who) drove the car with the emergency brake partly on. (That same driver couldn't understand why the car seemed to lack power and why there was smoke coming out of the right rear wheel for 15 minutes after the car was parked) The odd thing about that is, that I drove the car for several months after the incident and haven't needed to add brake fluid. It seems like if the cylinders were leaking bad enough to cause this problem, I'd be using fluid.

Brake fluid that has contaminated the shoes will cause the drums to lock up.
With the force of the car moving they usually brake loose with the noise you described. Change the shoes have the drum replaced or turned and find the leak usually a wheel cylinder is the cause of brake fluid leaks.