HELP!!! new mc and bleeding brakes???

[1997cobrasvt]

Ok guys I just installed a new master cylinder. When I went to go bleed the brakes (I know farthest from master cylinder first) when I open the little valve thing nothing is coming out. I bleed the master cylinder on the bench first.Then when it was on the car. then went ahead and went to the passenger right rear caliper and like I said nothign is coming out at all. What do you guys think? I have done quite a few master cylinders and bleed many systems and they have all worked out fine but this one is being a pain of course.

 

[1997cobrasvt]

also I should say that the emergency brake is working in the rear. And when I apply the brakes the fronts are only working.

 

[1997cobrasvt]

anyone??

 

[RoadZOmbie]

Sounds like air in the MC or bad MC seals, but also make sure the calipers are in the correct side Left/Right as the banjo bolt needs to be in the correct position in order to bleed properly but from your description sounds like the problem might be at the MC. Hope this helps good luck.

 

[1997cobrasvt]

I have a new mc and i bleed it on the bench then on the car with the two valves on the side of the master cylinder. and the calipers are on the correct sides (never took them off) No leaks either.thanks for the help though.anyone else

 

[1997cobrasvt]

i am leaning towards it being the brake pressure control valve. since that is what controls the spliting of the proportion of braking from the front to the rear.

 

[RoadZOmbie]

Aslo, isn't the MC hydrobusted by the lines from the Power Steering pump?

 

[RoadZOmbie]

i am leaning towards it being the brake pressure control valve. since that is what controls the spliting of the proportion of braking from the front to the rear.

Could be but is the pressure control valve a reason you are replacing parts? If not then it must be something else other than that.

 

[1997cobrasvt]

Ok soo ive been super busy with work and such ...but i got some time to work on the car today finally..

What i ended up doing is just tracing the problem from the rear.

I disconected the brake line in the pass fender from the line that comes from the abss unit. and blew air through it. and the air went through to the rear calipers .so i guess nothing was in the lines.

Then i disconeceted the line out of the abs to the line at the pass fender where they meet . I took it out and blew air through it went through fine.

So then i disconected the inlet fitting for the abs from the brake preessure valve for the rear and applyed the brakes in the car while the line was disconected to see if any fluid was coming out the pressure valve into the abs unit. sure enough none was....

So then I disconected the line that runs out of the pressure valve to the abs unit for the rears and applied the brake nothing came out.


Then to the final ttesst I took out the pressure control valve and applied the brakes and the master cylinder shot out fluid so I know its not the master cylinder .. ITs got to be the brake pressure control valve.Which is realy weird never seen them go bad before.

Well sorry for the long post guys had to get that off my chest been really pissed off about the whole brake situation for a few days.Probably hard to follow unlesss uve gone through the whole system.lol

O and thanks RoadZOmbie for all the help.

 

[Dano]

If that were my Cobra, I'd get plenty of brake fluid, then ... :

1. Fill master cylinder (Make sure you keep it full all the time)
2. Pump up brakes, and open Right Rear bleeder, and keep pumping until fluid comes out (close bleeder prior to each pump, or you'll just be sucking in more air).
3. Once you get fluid coming out - bleed it all the way.
4. Go to the next bleeder (Left Rear, I believe) and do the same.
5. Bleed the other two brakes

I know you said you've done this many times, but this is just my 2 cents.
You have to have a reliable person on the bleeder, or on the brake pedal too. If you use some jack-ass that doesn't understand how important it is to maintain pressure on the brake pedal, or when to open and close the bleeder, you may as well take it to a garage. FWIW, I wouldn't trust my wife to be at either end of the brake system - she'd lie to me in a New York minute:cryying:. JMO

Hope it all works out for you.

 

[1997cobrasvt]

Yupp I tottally agree with you. I bought a few bottles of brake fluid and I am just waiting on the new brake pressure control valve. I have to order it Monday. Then when it comes in,I will bleed away! Hopefully this solves all the problems with my brakes! Thanks Dano :beer: