Bleeding Brakes...

79jeepguy · 10-06-2006, 12:37 PM

I have an air pocket in my proportioning valve and after completly bleeding the brakes I cant get it out. I heard there is a tool used on the proportioning valve to fix this while bleeding. Anyone familiar with this or where I could purchase such a tool? 79 CJ7 Thanks

**CjinPA** · 10-06-2006, 12:51 PM

The tool is used to hold the pin on the front of the valve in. I don't know where you would get one but I suppose a big "C" clamp would also do the trick.

swampercj · 10-06-2006, 12:55 PM

There is such a tool but I have never been able to find it except on the MAC tool truck, which means it's pretty $$$. I have found that if you have a buddy push on the brake pedal, you can use a small pair of vise grips and gently grab the proportioning valve nipple (it will pop out with pressure applied to the brakes) and hold it out while you bleed the brakes.

I also use this trick for bleeding and have yet to find a brake system that we couldn’t get all the air out of…Take a 1’ or 2’ft rubber hose that fits very snug over the break bleed fitting, and plug or cap off one end of it. Then make about a 1” slit in the hose just above the plug and dip it into a bottle of brake fluid with enough fluid to cover the slit in the hose. What this does is gives the brake system a little pressure while you bleed, and helps force more of the air bubbles down the line quicker. Also the slit in the hose only allows fluid out and reduces the chance of air into the system.

Hope this helps and good luck!
Scott

79jeepguy · 10-06-2006, 12:55 PM

Well its a brand new proportioning valve and has a rubber grommet/cap over that pin of which you speak. It that supposed to be there for that purpose?

swampercj · 10-06-2006, 12:58 PM

You should be able to take the rubber cap off

79jeepguy · 10-06-2006, 06:26 PM

Is the pin supposed to stay out or in the valve? thanks again

swampercj · 10-06-2006, 07:06 PM

Depends on the valve. I believe on the Jeeps it gets pulled out for bleeding

swampercj · 10-07-2006, 04:53 PM

So did you get them bleed????
scott

SwampRatt · 10-07-2006, 08:42 PM

I've got a master cyl replacement job coming up. That'll mean bleeding the brakes. What the hell is a "proportioning valve"?

**CjinPA** · 10-08-2006, 06:20 AM

This is a proportioning valve. It is on the frame rail almost right under your brake booster and mc. This is where the lines from the master cylinder run to. It controls the difference in brake line pressure between the front and rear bakes.

SwampRatt · 10-08-2006, 08:37 PM

I've got a '73. I haven't seen anything that looks like the valve pictured. In the pic I have here the lines are one for the front, and one for the rear. Are prop valves for newer Jeeps?

**CjinPA** · 10-09-2006, 06:02 AM

Quote:

Originally Posted by SwampRatt

I've got a '73. I haven't seen anything that looks like the valve pictured. In the pic I have here the lines are one for the front, and one for the rear. Are prop valves for newer Jeeps?

The valve in the pic is for 82 to 86 CJ's. I am not sure if there is a valve on the 73. Don't take this wrong, but if you would fill in you profile (jeep specs) it would help in the future with responces to your questions.

swampercj · 10-12-2006, 01:03 PM

If it has drum brakes on all 4 corners it won't have one. If it has disc brakes on the front and drums on the rear it shouldl be down there somewhere

T Hoff · 10-12-2006, 02:49 PM

It's down lower then the master, it's on the frame under you butt.

Did you try reverse bleeding? That is taking the Wheel cylinders and pushing them in. Then doing the same with teh front Calipers or Wheel cylinders. this pushes the fluid up into the Master cylinder reservoir along with the air bubbles.
MAke sure the Master is not full to the top so the fluid has a place to go.