Jumper valve bleeding tricks?

J Banning

Quench my thirst with C16
May 25, 2001
I've got my jumper valve installed and the next step is to bleed the brakes. Aside from going by the instructions on gnttype.org, what's the best way to do this with the jumper valve in place? Will I have to do it twice... once with the solenoid open, once with it closed?

I'll be posting some pics on my Web site in the next couple of days for anyone that's interested.

After installing the jumper, I bled all four corners 4 times ( I also installed a brass combo valve at the same time as the jumper). I went to NAPA and purchased a Mity Vac to bleed the brake lines. This is a great tool, and is far easier and quicker than the pedal method. You will need to bleed the rear lines with the jumper valve closed and again with it opened. Do this atleast 3-4 times per side untill you are positive the air is out. I also hard mounted the jumper valve to prevent stress on the T connection and replaced the compression fittings w/ brass T's and flare fittings. Enjoy! Brian GSCA
Thanks Brian.

I also have a new brass combo valve and the Mity Vac. I thought I remembered someone else saying that I had to bleed the system with the valve closed, then open (sounds like a lot of fun!)

My jumper valve already has the flare fittings so there shouldn't be any problems there.

Thanks again,
Originally posted by J Banning

My jumper valve already has the flare fittings so there shouldn't be any problems there.


Which valve do you have?

I installed my jumper and have bled the system. I did the old pedal method with a friend in the car. A short clear hose and a clear pop bottle to catch the old fluid worked good too.

I first bled the system with the valve deactivated then energized the valve and bled again. I repeated this procedure twice. I went throught two quarts of fluid. I mounted my valve on the inner fender outboard of the Powermaster. This location makes bleeding even worse because the valve is near the height of the Master Cylinder and tends to trap air.

I don't have the engine back in and running yet so I haven't tested the valve under boost. I expect it will work just fine.

BTW I used double flare fittings instead of compression fittings. Call me CrAzY!

Banning, Are you saying that just your valve has flare fittings? (that is the norm) Are your T's Compression or double flares and who did you by it from? Brian
When I originally put the jumper valve together it had compression fittings. I installed it like that, but have since taken it all apart and redone it with 45* double flare fittings that I got from Sears Hardware (of all places).

Here's what I used:
- Two (2) 1/4" MALE t-fittings for splicing into the brake lines.
- Two (2) 3/8" to 1/4" adapters for the jumper valve to brake line connection
- Eight (8) 1/4" FEMALE nuts for joining it all together.

Note: There are also SAE 45* fittings made. They may be made of another stronger material besides brass, but I couldn't find them anywhere.

I placed the jumper valve on the frame under the powermaster unit. I also know someone who places their jumper valve between the frame under the drivers door. They drill a hole and mount the valve there with a bolt. I would of done it that way, except I had already started the job and had lines cut.

Hope this helps. If you haven't started the job yet, DON'T. Pay someone else for this headache!! I will NEVER do that job again, and I did it with the engine out of the car! I read somewhere else on this board where someone was quoting about 1-2hrs to do the job. I'd think 2+hrs (without a lift) if you were using compression fittings (don't have to flare the lines), but to do it with double flared lines... that's bull! Plan on 4+hrs

Absolutely, positively go with the double flared lines and brass fittings!!! The kit compression fittings simply DO NOT work. There isn't a human on the planet that can get them tight enough to stop the line from spinning and thus you will NEVER get the system bled. Save yourself an enormous amount of work, gallons of DOT 3 and trash the supplied fittings, go with brass and double flared lines and bleed it with the valve activated and closed as mentioned above, repeatedly until no signs of air are present. This is a great kit/idea that enables me to hold 16psi+ on street tires before I let off due to fear of flying parts :D, but the supplied compression fittings should be given to your favorite Mustang owner without question. :D