Brake bleeding..., sucks (pun woefully intended) Options

[Ductech]

Here is my two cents .... Yes these are all good methods of dealing with brake bleeding. I have had really good luck bleeding all kinds of motorcycle braking systems with my "Vacula" It's made by the swiss. and man It has always kicked ass. Now i have not bled a 914 but will be tomorrow, when i reinstall my pedal assembly.

I'll let you know how the power bleeder (vacula) works

[type47]

Question I have is about setting the brake pedal down with a wedge (2x4 to seat (IMG:style_emoticons/default/biggrin.gif) ). I read this How-to

http://www.pelicanparts.com/techarticles/9...leed_brakes.htm

didn't mention the step where you hold the pedal down (as if braking) and bleed the system in the usual way with the pedal down. What's the difference if you bled them with the pedal up? (IMG:style_emoticons/default/idea.gif)

[ctc911ctc]

All Brake GuRus, I have read all of the articles and there was not ONE mention of using a normal garage compressor with a MotiveProduct bleeder adapter.

https://www.motiveproducts.com/collections/...uropean-adapter

I can regulate at 15lbs, is there a -dumbass- thought I am missing on why everyone buys the pump bottle AND the adapter?

Many thanks in advance!
CTC911CTC

[twistedstang]

oh, i was following the pelican article:

"If your rear caliper has two bleed nipples (some have one, others have two), bleed the lower one first."

i haven't even touched the top ones yet. do I need to do both on each caliper??

2. Always bench-bleed the MC. That could well be be your problem all by itself. So much so that I'd remove it and do it even now.





Good luck

This right here!

[mepstein]

I just crack the fittings at the mc instead of removing it from the car

[76-914]

All Brake GuRus, I have read all of the articles and there was not ONE mention of using a normal garage compressor with a MotiveProduct bleeder adapter.

https://www.motiveproducts.com/collections/...uropean-adapter

I can regulate at 15lbs, is there a -dumbass- thought I am missing on why everyone buys the pump bottle AND the adapter?

Many thanks in advance!
CTC911CTC

No but there was an article on how to install a Schroeder valve in a reservoir cap so you could use the compressor. IIRC, the OP recommended setting the reg at 5psi. (IMG:style_emoticons/default/beerchug.gif)

[mlindner]

I just did mine after 25 years of all being apart. Rebuild MC new brakes front and rear. Had my buddy do all the pumping, nothing was happening. Put a little compressed air into the brake reservoir with a tight rag sealing the edges, bingo we have peddle pressure, no leaks, all good.

[Superhawk996]

I've had good luck in the past using a MightyVac to draw vacuum on the bleed screw and then having an assistant push the pedal to build pressure. Then rapidly open the bleed screw.

The combination of pressure in the system + vacuum on the bleeder results in more fluid velocity that will draw air along with it when the bleed screw is opened. As previously stated bleed from the top bleeder.

Tapping on the caliper with rubber mallet will also help move stubborn bubbles to the top.

Note: yes the MightyVac will pull bubbles past bleeder threads but these will not go backwards into the caliper - they are drawn to the vacuum source. Agree completely that with these bubbles flowing you cannot gauge the "success" of the bleed by whether there is air in fluid. In the end pedal feel is what determines success.

[Garland]

1. Bleed nipples are always on top. Air bubbles rise. If your only bleed nipple(s) are at the bottom then the calipers are on upside down... i.e. on the wrong side of the car.
Good luck

”wrong side of the car” Great Point! Pcar916

(IMG:style_emoticons/default/first.gif)

[930cabman]

must add a me too to the vacuum not working. Just like Perry said - draws air along the bleeder threads so you think there is still air in the system.

I have used the MityVac in the past with some success, but not much with our 914. Entire system was dry, I will try to pressurize the system from our shop compressor with 10psi.

[Ansbacher]

DON'T ignore bleeding those lower valves! If not done for a long time, you will not believe how much crud and garbage comes out of them. Bleed the lowers first then the uppers. I use the Motive bleeder WITHOUT putting brake fluid in it; just use it to apply pressure to the system. I add fluid to the reservoir between each wheel. No mess to clean up afterwards.

Ansbacher

[rhodyguy]

Adapting a larger container that could attach to the fluid reservoir might speed things up a bit. The in an out checking the level trying not to go dry is a pain. The level goes down fast when doing the rears. I think I have an extra cap (someplace) and will look for a fitting that fits the hose and put it in the cap.

[Al Meredith]

I think it has been mentioned here before but I remove the bleeder screw and insert a tapered plastic fitting ( usually included with the vacuum device) that way the air sucking around the threads does not bubble.

[930cabman]

Our 1975 project was missing a rear caliper, both front caliper's were loose and there wasn't a drop of brake fluid in the system. I had a Mityvac but have not used in several years. It appeared to be working, but didn't have enough vacuum. I installed a fitting to the brake fluid reservoir and pressurized the system to about 5 or 10 psi. Just had time to work on the rears today and the pedal is getting firm without doing the fronts. It is looking like the pressure method is working better than the vacuum system.

[andys]

When vacuum bleeding, I put grease around the thread of the bleeder valve where it enters the caliper. Stops the bubbling. Clean when finished.
Andys