I recently disconnected the brake hoses on the '98 OBW to do a strut job. Reassembled, bled the brakes, car was fine for two weeks. Noticed a puddle under the car this morning... turns out it's leaking brake fluid from around the banjo bolt/ washers, despite the bolt being nice and snug.

 

I will be replacing the washers, cleaning the surfaces and giving it a good test, but why did it last so long without leaking? I always thought that it either leaked or didn't, and I did apply good firm pedal pressure to check for leaks after the initial reassembly.

 

As a side note, I noticed a tiny divot in one of the washers, so I suspect a piece of debris got in there... but once again, how could it have ever sealed at all?

 

Nathan

Why didn't it leak? Who knows. Those are called crush washers for a reason. They are really only 1 time use....

I've had them be perfectly fine... until I started the engine. Once the booster works and I stand on the brake nice and hard it will start to leak. I always check new banjo bolt washers with the engine running before even putting the wheels back on.

 

I'd guess it was leaking the whole time, just not very much at first. Whatever debris caused the dimple in the washer may have been blown out by applying the brakes to stop down hill. Hard to say.

Thanks for your replies. I'm pretty sure it was not leaking from the get-go (I did stand on the brakes with the engine running...even a small leak will result in the pedal sinking slowly....but who knows?) It'd have to have been a tiny leak to have not emptied the reservior to the add line in two weeks of stop and go city driving...

 

I read that it's possible to re-use these copper washers by heating them with a torch until they glow... I tried it (was hoping to get the car on the road and the dealer was closed) and it did a nice job of restoring the non-divoted washer to a smooth finish. The one with the divot was too badly messed up.

 

We got some fresh washers from the dealership today. I'll inspect the hose, banjo bolt and caliper finish very carefully prior to reassembly.

 

Nathan

Heating them like that is called annealing. It can work but sometimes it's better to just get new.

I've reused hundred (maybe thousands) of copper washers over the years (not just on brake systems). 99% of the time they are fine. Occasionally you have to replace one but it's generally the exception.

 

GD

GD- yeah, but it's that 1% of the time they don't seal that can bite you in the rump roast! Kidding aside, I've never had a problem w/o changing them before on many different cars.

 

New washers in, bled the system, nice firm pedal, no signs of leaks. Being slightly paranoid about it now, I'll keep a close eye on the fluid level for the next couple of weeks.

 

Nathan

I've reused hundred (maybe thousands) of copper washers over the years (not just on brake systems). 99% of the time they are fine. Occasionally you have to replace one but it's generally the exception.

 

GD

 

I've replaced hundreds, (maybe thousands) that people have reused and leak. Thats why I just use new. It's a small expense and usually not worth the hassle if the old ones leak. I have a huge assortment of them.

It's probably due to the corrosion you guys have. I've never seen one leak here. All the copper washers I've had to replace have been on industrial equipment - not brake systems.

 

I would imagine the copper doesn't mix well with the salt and unpainted castings very near to the road surface

 

GD

^^True, most of them I see are completely rotted most of the time. Along with everything else

 

Gotta love the rust belt.