Brake fluid resevoir only half full.....
 

Hi everyone,
I replaced the brake fluid resevoir and resevoir grommets and filled up the tank with DOT4 brake fluid. Problem is, only the rear area is full with fluid. What gives? The brake pedal is a lot firmer than it was before, but it's still a bit mushy and I can still hear a slight hissing sound coming from the engine compartment when I press on the brake (with the engine off). Please advise as to what I should do. How do I get fluid in the front of the resevoir? Thanks

Alex

I forgot to add that my car is a 1983 300D Turbo with 119,000 miles on it. The brakes never acted up until I tried to vacuum bleed the brakes last week so I don't think that it's the master cylinder that's bad. Ok, thanks

You can also refer to my last thread "HUGE brake problems...." for more info, or ask me and I'll reply promptly

Alex

Alex,

It seems your fluid is leaking out of the front chamber or from the part of the master cylinder the front chamber is connected to. When you fill it up, there is only one place to pour the fluid in, and it is supposed to fill the front chamber then overflow over the partition and fill the aft chamber. I am not positive, but I think the two chambers are connected to two separate brake circuits. I could be wrong there, but it seems the front chamber should be full to start with, then either the fluid is draining down into the brake lines to fill them, or it is leaking out. Have you tried filling it up again and letting it sit? Has any fluid appeared either in the area below the master cylinder or under the car? If you let the lines drain down you should expect to put a couple of the smaller cans of brake fluid into the reservoir to fill the lines and fill the reservoir. If you have any further data, please pass it on. Jim

Thanks so much for the reply but I got the problem fixed already. The rear chamber was empty but I was too stupid to notice because the resevoir exterior was so dirty.

I'm glad to see your problem fixed. You possibly missed my post in the following link:

http://www.peachparts.com/shopforum/showthread.php?threadid=21494&perpage=15&pagenumber=1

Have a nice day.

David

Just to avoid running into the dry rear portion, I always top off the MC after bleeding each brake. Especially important when doing a complete drain/flush/refill as the new fluid is nearly invisible in that opaque reservoir.

Also, if after the third crack of the bleeder, there is still air, I'll top off the reservoir before going for a fourth.