brake bleeding

[goatijoe]

I replaced the master cylinder today and went about bleeding the brakes like always had worked farthest away to closest. Now i don't have a good pedal now. Is there a wrong way and a right way to do this? and another question i have where does the vent tube on the top tie in to on that line? where does it go?

 

[Digger09]

The vent tube goes up the front of the firewall. Not sure about the bad pedal though. Sounds like your bleeding it right to me.

 

[doghead]

Did you bleed the air pack first?

Did you use a power bleeder?

Follow the vent line, it's about 4 feet long. It may go up near the air filter housing(MWO) or it may tie into your road draft tube.

 

[goatijoe]

No i did it the old fashion way with someone else pumping them. so i need to start with the air pack then move to the right rear and work my way across the tandems then to the front. Is there a better way to this than that way? I'm always open to new ideas on doing things might find a way that works better than mine.

 

[doghead]

That's the correct order.

Dot 5 can and will trap tiny bubbles when pumping it alot.

Wait til tomorrow, and feel the pedal. Then, consider re bleeding if needed.

 

[seabeeut]

search for pressure bleeder's I used to do it with pedal or vacum
then read the post's here on building your own PSI bleeder
what a difference I will never go back also you can do it yourself
you don't need two people.

 

[goatijoe]

Ok ill do that tomorrow I have got to get some more fluid tomorrow. I about ran out. The thing with starting with the air pack is wrong with the way I have always done things starting with the farthest out working closer. Thanks for the heads up on where i need to start. Do you know why Dot 5 will trap air in it?

 

[doghead]

It just does, and by manually pumping the brake rather than use a power bleeder, you make a lot of bubbles.

Look inside the MC res while pumping the pedal, you'll see what I'm talking about.

 

[goatijoe]

Seabeeut- I saw some of the ideas that they had for that i might just make one. I use a board or stick to hold the pedal when i don't have someone to help. Don't ask old boss man of mine taught me that he was from the old school back when tractor trailers had no air brakes just hydraulic brakes. I had my gf pump and hold them today.

 

[dozer1]

http://www.steelsoldiers.com/deuce/3229-deuce-power-bleeder-r4x4-style.html This is your friend. No doubt, the most useful tool you can build for your MV. Not expensive to set up either. Watch Heavystevens video towards the end to get a look at how to use your pressure bleeder.

 

[O.D. Fever]

Keep the master cylender full, I don't know why but it makes a big differance.

 

[goatijoe]

Ok yall, I bled the brakes again and i will get a hard pedal sometime and them sometimes not. i get a real good pedal after a few pumps. i can hear the air pack working, none of the wheel cylinders are weeping fluid. i don't know what it could be.

 

[doghead]

Have you done a wheel bearing service and full brake adjustment yet?

Why did you change your master cyl to begin with?

 

[goatijoe]

No, i haven't done any of that yet. I have checked the wheel bearings and they have no play in them. I don't have much experiences with the working on the brakes on them. I have worked on all different style of truck brakes but this is the first that has had a air powered booster. I changed the master cylinder because of a problem with it not wanting to stop good and its what every one said it was.

 

[doghead]

How long has it been since anyone has serviced and inspected your brake system?

If the shoes are not adjusted properly, the pedal will be low.

Please explain , not wanting to stop good.

where did you get a new MC? Did you inspect it throughly before installing it?

 

[goatijoe]

I looked at them when i first got it and everything was good on them. When i first got it it would stop on a dime and hear recently it got hard to stop. It would stop but not real fast when the pedal was almost on the floor, if i pumped them it would stop good. Sometimes i had a good pedal right off and it would stop on a dime. It acted like the fluid was bypassing around the plunger. I got the MC from Jim Henry and i did inspect it everything looked good on it. The MC was a nos with all the plugs and everything rust free .

 

[doghead]

Well, you need to do a 100 % visual on the rest of the system.

I would rebuild the air pack next. And pull the hubs and rebuild all wheel cyls.

 

[dgardner]

Did you bench bleed the MC before installing it? Sometimes air can stay trapped inside a MC because the pedal won't run it full stroke. Power bleeding might take care of that but maybe not.

 

[joshs1ofakindxj]

I think the total cost of building a pressure bleeder for me was less than $20 for a weed sprayer bottle and some brass fittings. I also installed a remote brake fluid reservoir and pressure bleed at the cap there.

Don't go over 6-8 pumps of the sprayer. I blew out the seals in my master cylinder and had to hone and rebuild it.

 

[goatijoe]

THANK YOU ALL!!!! It is all fixed and rolling again. I took all the wheels off and inspected the whole brake system wheel cylinders are all good just the brakes where way out of adjustment. I had to replace the master cylinder due to leaking from the plunger side so you have to start with a known problem and go from there. She stops good I almost went thou the windshield when i hit them. Hopefully i wont have any more problems.