Proportioning Valve

[Shawn]

I have a 86 CJ7 that I'm having rear brake problems with. It has an auto tranny and when the snow flies the front locks up and the rear keeps pushing. I have spent all day replacing parts with no luck. It seems like the rear just doesn't have enough pressure to stop the wheels from spinning. I can apply the E brake and it stops it just fine.

He is my thought. If I bypass the stock Proportioning Valve and add in an adjustable one do the think that will help?

Any advice would be great.

 

[jdub]

I have a wrangler one if that would help. I have had the same issue and I swapped in a wrangler booster to give me more power. I'll see if it works, can't now cause I'm in California. I don't know if the fittings are the same but you could adapt them with some parts from napa.

It's yours if you want to try it.

It is the motor that is doing it. I don't know if it is the idle that could be turned down cause the "snowmobile" effect is scary.

I just bump it out of drive and then you stop fine.

 

[Shawn]

Thanks, I also have a wrangler one. Just really not wanting to go down that road.

 

[jdub]

I'll let you know if the change in brake mc(which was from non power brakes) makes any difference in the snow.

I'd like to find out if there is any way to resolve this. We have slowly slid into intersections and even bumped someone that was sliding too.

 

[bryson]

I think the idea of ditching the stock valve and plumbing in an adjustable one is the ticket. I know of many people that have done that with very good luck. CJ proportioning valves are notorious for this problem.

 

[DaveB]

My old 77 cj7 had the exact same problem. It was so bad we named it the red sled and pretty much gave up driving it in the snow. I should have tried swapping out the proportioning valve to see if that would have helped. Keeping the rear brakes adjusted properly also helps. If you want to try an xj proportioning valve I have several but I'm not sure how much better they would be.

 

[Shawn]

So for future reference, I pulled the rear restricting valve out of the back of the p valve. Basically, you remove the rear brake line coming out of the p valve. Then there is another larger housing behind the rear brake line in the p valve. I removed that to gain access to the flow valve. Removed it and threw it away. What this did was create a leak in the side of this housing,,, there is a pin hole that looks like it is there to allow excessive fluid out?? I cleaned out this pin hole thing, laid down some JB weld and screwed in a small screw into the pin hole. Let is sit over night, installed it all back and now I can lock up the rear.

We will see how the snow driving goes.