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Brake help please - this can't be good.

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I

ichthos

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I bled the brakes and slave cylinder last weekend. I was having a problem gaining access to the the slave cylinder, so I decided to rebleed to make sure I got all the air out. Next I decided to adjust the handbrake. I was having problems getting it to work, and then discovered the brake pedal was very loose and spongy. I decided to rebleed the brakes again. I hooked up my Eezibleed system, and opened the bleeder valve on the left rear brake - nothing. Tried the right rear brake-nothing. Finally I had my dad push the brake pedal while I tried to bleed the rear back brake. This time fluid came out, only it was black. This can't be good. All parts are brand new. I used Castrol LMA brake fluid. The fluid coming out of the slave cylinder was clear. Am I correct in my conclusion that the new rubber parts in the wheel cylinders only deteriorated? It has been a few years, but I am pretty sure I bought them from Moss. If it is the rubber in the brake cylinders, does someone have another source for these parts?
Any help would greatly be appreciated.
Kevin
 
I wouldn't worry about the color too much- bleed it a bit more until it clears up and you should be fine, that is not too uncommon after a complete rebuild.
BillM
 
Personally, I would be VERY concerned about black.
You're talking BRAKES here.

The only place black comes from is the rubber, and generally happens with a poor changeover from DOT 3/4 to DOT 5 and vice-versa.

I would want to know where the black was coming from.

Possibly just "old" fluid in the lines gone "bad", but doubtful.

Keep bleeding, see how long it takes for the fluid to run clear.

Very short period of time, cylinders.
Little longer, hoses.
LONG time, master cylinder.

You ever had DOT 5 in it?
 
I am doing a total restoration on my Bugeye. I have never had brake fluid in my car until last weekend when I added the Castrol GTLMA. I have brand new stainless steel lines. I had the master cylinder resleeved and rebuilt by Apple Hydraulics. The brake cylinders are brand new from Moss (the old ones had been frozen for years - I couldn't get them apart.) I am going out to rebleed the front brakes after dinner and see what color comes out from them. I will post a reply once I bleed them and the rear brakes.
Kevin
 
bleed till it comes out clear.
 
Could be some new-fangled assembly lube, but the stuff I still have is clear.
New hoses?
 
New hoses. I took apart all 6 wheel cylinders before I installed them this summer to inspect them since they had been sitting for ten years. I think the lube was either green or red - I can't remember now.

So, here is an update. I rebled the front brakes, and they came out clear with no air. I tried to bleed the back brakes again. After bleeding half a bottle of brake fluid, they still came out dark black. Doesn't that mean the rear brake cylinder rubber parts have to be breaking down? And doesn't this mean I will have to put new rubber parts in the rear cylinders? I checked my records, and both the front and rear brake cylinders are from Moss. I am sure they will not deal with me now since they were bought so long ago. I want to go with another source. Can someone recommend someone they have bought from recently for a rebuild kit?

Kevin
 
Break fluid is cheep, run the rest of the bottle through. Consider the rear hose. I would not expect the cylinders unless they were leaking as well.
 
I didn't even think about the hoses. Once you said that I checked through my records. I ordered new hoses for the front, but I found no record of new hoses being ordered for the rear. It is too dark for me to see what the rear hoses look like right now. Maybe that is the problem. I will check tomorrow when I have more light.

One thing that puzzled me was that I could see no leaking fluid anywhere, and the master cylinder had not gone down. If the rubber in the cylinders was breaking down would it be obvious? If they were the source of the black fluid, would they start leaking? Would I need to remove the rear drums to be sure?

Kevin
 
Yes, they'd start leaking.
If the front came clean fast, that's probably okay.
Rears, change that hose.
You did replace ALL the steel lines, right?

Just for clarification, you changed the lines and put the old rear flex hose back in?
 
I replaced ALL the lines with stainless steel. The front rubber hoses were replaced, but it looks like for some reason I reused the rear hoses. I know, not too smart. I probably looked at them and thought they looked OK at the time. It looks like the problem is the hoses, but I am going to pull one of the rear drums just to be sure. I guess if all I have to do is replace the hoses, that will be an easy fix overall.
Kevin
 
I would replace the rear hose in this case and press on. Hoses are good and can be trusted for 10 to 20 years depending upon storage conditions and quality at purchase.

For future thought, if you have to replace one replace all.
 
The moment I read your original post I thought "he didn't replace the rear hose".
 
In retrospect, I know I should have replaced them. Who knows how old they were. They looked fine, with no cracks or visible damage to the rubber on the outside. I guess this is an easy lesson compared to what could have happened. When I finally get out there to look at them in daylight, it should be intresting to see what they look like now.
Kevin
 
Just read this, same reaction as Dave. The hoses can deteriorate from the inside out! Even to the point where they will act as a one-way valve and LOCK the brakes. The first evidence was if the Eezi-Bleed didn't push fluid and it required pedal effort to get fluid out of the rear cylinders. Hose replacement!!!
 
I have always inspected brake hoses by just examining for checking or leaks. Obviously my method doesn't work. If you can't look at them and make a judgement, is this similar to tires in which they just need to be replaced within ten years no matter how they would appear? How else can you guarantee the safety of the brake lines?
Kevin
 
Yes, prb 15 to 20 years but better safe than sorry.

Size of wrench depends upon bleed valve, and I am not being smart, 10MM or maybe 3/8th box end is best.
 
I used the Eezibleed system so I could do it by myself. There is a rubber access panel on the passenger side of my Bugeye that exposes most of the slave cylinder. I used a 7/16" wrench to loosen the nut, ran a plastic tube into a bottle, and let enought fluid run until all air was out. It was actually pretty easy after other forum members helped me out.
Kevin
 
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