Engine/Transmission (1994 - 1998) Brake help needed

[jsjaastad]

1995 3/4 ton 4x4 88,000 miles. Brakes were getting kinda spongy and sometimes the pedal would go clear to the floor during a panic stop. I replaced front pads and rear brake shoes, same problem. I looked in my 1995 service manual and followed the trouble shooting guide on page 5-7 master cyl/power booster test. After doing the test several times I replaced the booster check valve and the master cylinder, pump checked out okay. Bled the master cylinder as per instructions and same old thing happens.

I have noticed that when you pump the pedal (motor off)you can hear air escaping under the dash. After the pedal becomes hard and you start the truck the pedal will go straight to the floor. This does not happen on my friend's 96.

I am beginning to think the booster is the problem, but the dealer wants $240. 00 (American) and the closest one is in Denver which is 4 days out. I will probably order the booster, but was wondering if anyone here had any ideas.

Thanks in advance, Tom/Idaho

 

[hsmith]

Doesn't sound like a booster problem. If it is RWAL it probably needs hydraulic dump valve, located beneath the MC

 

[jsjaastad]

It is RWAL. Is there a way to check the hydraulic dump valve? I have a service manual and can not find any reference to this valve. Mine has the RWAL valve beneath the master cyl and the combination valve between it and the fender. Any assistance is greatly appreciated. Tom/Idaho

 

[southpaw]

I went thru same problems on my 93 all kinds of brake work by a local shop they couldn't fix it so I tried . I cleaned the master cyl. it was full of junk then bled the entire system many times still didn't work. Took it to a dodge mechanic He replaced the RWAL and used a pressure bleeder to remove all the air . I paid big bucks for the RWAL but later learned I could have bought the same unit at napa or other parts store for around $100. There is also a very good discussion here about elimination of the RWAL by a x dodge employee . Do a search on brakes or RWAL . I wish I had known this troublesom unit could have been eliminated before all those $ i spent for something that works not real well. good luck

 

[hsmith]

If the ABS light is on, you can access the trouble codes by temporarily grounding pin 13 in the OBDII connector with the key on. This will cause the light to flash codes. You can then use the code chart to see which part is malfunctioning. If the light is not on, it will not go into diagnostic mode. We have fixed a lot of earlier GM with the same RWAL just because we knew of the problem. Just did a '96 Ram today, but was able to retreive the codes from the module which led us to the valve. This valve will give the same symptoms as a master cylinder that is bypassing. Hope this helps.

 

[jsjaastad]

I will try to do the code thing today. Not sure if that will tell me anything because I do not have any fault lights coming on.

Does anyone have the NAPA part number for the RWAL valve? Does it hook right up or do you need special connectors?

Would replacing this valve eliminate the sound of air escaping under the dash when I push down the pedal with the motor off? Appears to me this air can only come from the booster as I can not find any other air lines under the dash.

Thanks again for all assistance, Tom/Idaho