Help with brakes

[jerseyjeep2003]

When I bleed brakes I do not use the vent line until I am done. I also use the time tested method of using a hose on the bleeder with the other end in a bottle with BFS in it with the end under the surface and I pump the pedal a couple of times and then add more to the master.

This is the one fact that you need to know. The master contains enough extra brake fluid to push the pedal all the way to the floor a maximum of three times.

If you think you have a brake line leak while on the road, this will limit how many times you can pump the pedal before you are out of BFS in the resevoir.

A remote resevoir will increase this of course.

I mad a remote reservoir and a pressure bleeder, great ideas.

My process for bleeding the brakes:
1. fill remote reservoir
2. attach pressure bleeder to top of remote reservoir and "pump up" sprayer tank.
3. bleed airpack at bleeder valve AND lines into slave cylinder (redundant, but can't hurt)
4. check level of brake fluid and pump up sprayer again
5. bleed at RR wheel, LR wheel, RF wheel, LF wheel (checking fluid level and pressure accordingly
6. remove pressure bleeder
7. start engine and test brake pedal
8. repeat process with engine running if necessary

It was after I started the engine and built air pressure in the tanks that I noticed air bubbling into the reservoir when applying the brakes. This in turn introduced air into the system again as it was bubbling back from the MC. So the gears started turning......WHY and HOW would air be back fed into the hydraulic system. Only 3 ways that could happen: 1. faulty airpack (but, it was just rebuilt) 2. leak in a brake line component (couldn't find any leaks) 3. a vent not allowing the venting process......BINGO. I then removed the orifice plug, bled the system AGAIN and everything worked as it should. Not that this would always be the answer, but, certainly much easier than tearing everything apart. I saw a thread with a military correction on the venting configuration somewhere. Basically I think it separates the brake and fuel system vents as they are sometimes interconnected and apparently caused an issue at one point. I will be looking into that in the near future.

 

[Katahdin]

Thanks for letting us know about the problem and fix. I'm going to clean that vent the next time I'm under the hood for good measure.