I have cotton brakes

krazyskip · 10-07-2003

I changed the brakes in my 86 to 11'' brakes with 73mm brake calipers. When I went to bleed the brakes I forgot to check if there was enough brake fluid in the master cylinder and I think some air got in. So I went to put some brake fluid in the master and I found some greasy clay like substance in the reservoir So I cleaned all the grease out of it and continued to bleed the brakes. Now I have all the air out of the lines and the brake fluid runs clean but the brake peddle feels like cotton. The brakes don’t grab at all. Did the master cylinder go? What happened?

Jarrett · 10-07-2003

Did you bleed the rear brakes as well?

krazyskip · 10-07-2003

lol yes i did all 4 two times for good measure.

Jarrett · 10-07-2003

Rear drum / front disc?
Stock 86 Master Cylinder?
What Prop Valve?

krazyskip · 10-07-2003

YES REAR DRUM/ FRONT DISC
yes Stock MC.
prop valve what ever came on the 86 lx.

GhostDog 5.0 · 10-07-2003

When I changed my master cylinder about 3 weeks ago, I had to bleed the back several times to even get it flowing. The lines had a lot of air. I thought I bled it enough but it just needed several times (about 20 or so).

That clay substance worries me.

krazyskip · 10-07-2003

Yes the clay worries me too. My friend said that maybe the clay has broken my seals inside the MC, and when I did the 1st bleed by myself that I might have pulled the clay in the MC. And now the seals wont close any more.
The brake fluid goes through the caliper it just doesn't have enough pressure to hold them tight.
Is there some way I can move the internals of the master cylinder maybe it is just stuck because of the clay?

marks86gt · 10-08-2003

Usually the master cylinder internals are just held in with a retaining ring but you'll have to remove it from the car to do this. You might find that one of the packings on the mc is screwed then you're looking at a rebuild or buy new. I highly suggest getting a new one, it's not worth trying to rebuild.

krazyskip · 10-08-2003

ok thanks

79cobra502lx0 · 10-10-2003

could you have mixed brake fluids like dot 3 and 4 i think will make the clay like substance...atleast i think it was them 2 it might well if that occured you might have blown your seals i just replaced a master cylinder myself and struggled the same as you have except for...without the clay stuff.....i had a huge leak in my master cylinder and after school one day on my way home aparrently it had all leaked out and i had to put it all the way to the floor but all it did was slow down but i couldnt stop so i just down shifted the rest of the way....that is how i figued out that we had a leak somewhere so i replaced that and checked to see what fluid was in it and i bought the same fluid....dot 3 and bleed the rear about 3 times before i got it...i didnt like doing that......

krazyskip · 10-11-2003

i had to tow it out to the shop. lol i was trying to save money buy doing the brakes my self. now i am going to pay two times.