2nd Gen Non-Engine/Transmission Brake woes

[sonorakitch]

Hi All,



My 94 is having a bit of brake trouble, and I would love to diagnose it here (I am not too good with brakes). If I am at low speed, and mainly idling, and depress the brake pedal, occasionally I lose my power brakes completely and both the ABS and brake lights come on. It is most dangerous when pulling into that tight parking spot, knowing you have to come close to that car next to you, and going for the brake---not much of anything. Needless to say, it has made my heart stop a couple of times.



Thanks in advance!

~Chris

 

[rjones]

How hi is the idle set? You may need to bump it up a little,mine was doing that, cause it would idle at 500 in gear and not create enough vacuum,so I raised the idle to 950 and solved the prob... . Rick

 

[sonorakitch]

Hi there Rick,



My idle is at 650 with AC on, 760 with it off. If you suspect this is too low, I can notch it up some... . there is nothing wrong with a little higher idle... bothers the neighbors more!!! Ha ha, really, I just hope it is not a brake issue, although it does feel like the system is losing pressure somewhere. When I check the fluid though, it is fine and never loses a drop. I am slightly baffled!



Thanks,

~Chris



P. S. -Any other input out there?

 

[baby.driver]

I once had a van where when you applied the brakes they would keep moving toward the floor even after the van stopped. Brake fluid always up, no visible leaks... ... hmmm.

Turned out that both of the front flexible lines had holes in them, underneath the heavy rubber sheathing. You could see the blister grow when applying the brakes and shrink again when you let off. New lines, problem solved.

 

[sam peterson]

Chris---When the problem occurs, does the pedal stay up & hard or does it go down part way? If the pedal goes down your RABS valve may be bypassing. This would turn on the ABS light and dump you rear brake presure. You could also be getting a bad vacuum pump if the pedal is up & hard. ---Sam

 

[rjones]

Originally posted by sonorakitch

Hi there Rick,



My idle is at 650 with AC on, 760 with it off. If you suspect this is too low, I can notch it up some... . there is nothing wrong with a little higher idle... bothers the neighbors more!!! Ha ha, really, I just hope it is not a brake issue, although it does feel like the system is losing pressure somewhere. When I check the fluid though, it is fine and never loses a drop. I am slightly baffled!



Thanks,

~Chris



P. S. -Any other input out there?

Oh I didnt see that you had a 5 speed... I have an auto and it fixed my probs however I set mine to 750 w/ac on and in gear... . You can try but I dont think it will help... . if your sure there is no leaks in the lines I would say that your vacuum pump might be going... I would try higher idle before buying a vacuum pump though... . good luck... ... Rick

 

[sonorakitch]

Hi All,



Thanks again so much for the help. Sam- the pedal stays up and becomes hard... it does not go to the floor. And again, the Brake light and ABS light both come on.



~Chris

 

[jbrown9709]

My 94 does the same thing. I don't think that anything is broken, the vacuum pump simply does not make enough vacuum at idle to keep up with rapid brake applications. It has been suggested that one could add a vacuum reservoir, but I find it's easier to just keep a constant pressure on the brake pedal when navigating tight areas like parking lots rather than repeatedly applying the brakes. I believe this is one of the major reasons Dodge went to hydraulic boost brakes later in the nineties



Jeff

 

[illflem]

Jeff's advice is right on except that losing vacuum won't cause the warning lights to come on. Your problem is in the brake system, not in the vacuum system.

 

[jbrown9709]

OK, now I'm worried

When my truck does this, my brake and anti-lock lights come on also. Any ideas

 

[BillGotthelf]

I don't know but with the pedal hardening up at the fully extended (away from the floor) position it sure sounds like a vacum pump or leaking line.