how to check hydroboost.. goes right to the floor

[84cucv1ton]

MC is new. thought that was my problem... never had a problem like this.. not sure where to start. as alwys thanks

 

[kassim503]

If the pedal goes to the floor its probably not a hydroboost issue, rather the hydraulics itself.

Is there any leaks anywhere? Are you sure the brakes are bled properly?

FYI pressure in the rear system is what makes up the pedal feel in the system, ive seen a soggy weak brake system caused by a adjuster wheel that fell out of the rear drums

 

[BIG_RED]

Sounds like you got a new bad MC. Try capping off the break line ports with the plastic plugs it came with. If you can't push it then - you've got break trouble. If not, your new master is no good. Pretty sure there is mechanical link straight through the hydro-boost. So if it's shot it just won't "help" you apply the breaks, you should still be able to apply the breaks. There is also some sort of metal piece that goes between the MC and the hydro-boost. Mine stayed on the hydro-boost when I swapped my MC, but if it's missing I don't think anything works (not enough travel in hydro-boost to reach the mc without this extension in place). Good luck!

 

[197thhhc]

Did you bench bleed the new MC before you installed it, Have you thoroughly bled the brake system. Was the old MC doing the same thing.

 

[Matt65]

Verify Power Steering fluid level. As it gets low it will pulsate while steering and braking as the Power Steering fluid gets low. Try to find and repair the leak if this resolves your problem.

 

[nattieleather]

Not trying to be rude but did you RTFM? (Read The Field Manual) The -20 for this truck will give you lots of information on how to troubleshoot your system. I have to agree with 197th did you bench bleed the MC and then bleed the whole system?

 

[chuck0070]

Had a similar problem recently, my brake pedal went to the floor and took a pump or two to get a strong pedal.... Brakes lines had no air in them... I thought maybe the MC. Then I pulled off the rear drum hubs and noticed the brakes were way out of adjustment and the adjusters were stuck and non operational. Some brake cleaner, tightening of brake springs and some manual adjustments to reset the brake shoes and I now have a full strong pedal. The brake cleaner loosened the adjusters and they are now working fine.

 

[84cucv1ton]

wow lot of good info.. no i didnt bench bleed it.. someone years back told me its not really needed.. i got it bolted it on bleed them with a friend.. i will pull it off and see if that the problem. will test it.. thanks guys

 

[84cucv1ton]

do you really need to bench bleed?

 

[45FMJoe]

Verify Power Steering fluid level. As it gets low it will pulsate while steering and braking as the Power Steering fluid gets low. Try to find and repair the leak if this resolves your problem.

That was the problem in my M1009 when I picked it up. Had no power steering and barely any brakes. Filling the power steering reservoir with fluid fixed both problems but the fluid drained slowly from the steering box. My truck is in FL with all the rest of my stuff but my dad says the box may have stopped leaking. I can't wait to get it up here (along with my dog and all my stuff) and start working on it.

 

[kassim503]

do you really need to bench bleed?

yes!! you will never be able to get all of the air out in car, the pedal will not do the full stroke of the mc like bench bleeding.

 

[84cucv1ton]

ok good to know thanks