Brake bleeding problem, Post axle swap

[2slow4you]

Swapped out some rear axle shafts on my buddies 92 Toyota Pickup.

When the truck is turned off we can get the pedal to build a slight amount of pressure, but when it gets turned on the pedal goes to mush and will not getting any better no matter how much we bleed the lines.

No leaks or bubbles anywhere as well.

Is it possible that we have to bleed the front as well? Even though we didn't touch the front lines?

Any ideas?

 

[WHITE TRASH1]

If the master drained empty while the brake lines were open then yea, the front needs to be bled.

 

[2slow4you]

If the master drained empty while the brake lines were open then yea, the front needs to be bled.

The master didn't get passed the min point on the reservoir.

 

[Damnyankee]

i'd try bleading teh front. all it takes is a bubble to get in there.

remember, start at the furthest point from the master. (as the line goes)

 

[2slow4you]

Will starting before the the last line cause any hiccups? I had a brain fart and started at the Pass. Quickly realized the mistake and did it all over from the drivers side. I'll swing by his place and bleed the entire thing and see what happens.

 

[Damnyankee]

Will starting before the the last line cause any hiccups? I had a brain fart and started at the Pass. Quickly realized the mistake and did it all over from the drivers side. I'll swing by his place and bleed the entire thing and see what happens.

depends on your vehicle and the routing of the brake lines.

on my rig, furthest away from the mc is the passengers side.. before the new axle it was the drivers side.

which LINE is longest?

 

[JOOP]

Your probably bleeding it wrong.

Open up bleeder, then have someone push and hold the pedal, Close bleeder, Repeat until no air.

If you guys are pumping up the brakes, then opening the bleeder your not going to get the air out.

 

[2slow4you]

Your probably bleeding it wrong.

Open up bleeder, then have someone push and hold the pedal, Close bleeder, Repeat until no air.

If you guys are pumping up the brakes, then opening the bleeder your not going to get the air out.

Maybe that's my prob, I've always been told to build line pressure (pump brakes), hold brake to floor, open bleeder, then closed bleeder, until there are no more signs of bubbles.

 

[zukkev]

Also Justin, try not to let the M/C travel to the built-in 'hard stop'; this can sometimes damage the seal in the m/c....I have the helper push 1/2 way and hold while I crack the line. You should hear air coming out til the air is purged....repeat process till all wheels are done.

 

[zukkev]

Maybe that's my prob, I've always been told to build line pressure (pump brakes), hold brake to floor, open bleeder, then closed bleeder, until there are no more signs of bubbles.

No need to pump...if the m/c is good, it should instantly start building pressure/pushing fluid...in fact pumping can aireate the fluid, making the bleeding process take longer than it should!

 

[2slow4you]

Also Justin, try not to let the M/C travel to the built-in 'hard stop'; this can sometimes damage the seal in the m/c....I have the helper push 1/2 way and hold while I crack the line. You should hear air coming out til the air is purged....repeat process till all wheels are done.

No need to pump...if the m/c is good, it should instantly start building pressure/pushing fluid...in fact pumping can aireate the fluid, making the bleeding process take longer than it should!

Wow that makes a lot of sense. Thanks Kev.:awesomework:

 

[Boogievan]

I may be putting this in a little late, but your Toyota also has a bleeder on the goofy proportioning valve that's above your rear axle... If it's the same as my Toyota, that valve also has a return line that runs into a distribution block in the engine compartment. If you introduce air into the system, it can get into that block, and get pushed into the whole system. Gotta bleed em all.

 

[YoMamasTaco]

Some input:

The rears are getting plenty of power. In fact, they are locking up on braking.

What is weird, is that the pedal travels about half the throw, then grabs hard. Normally (as far as normal goes. haha) it should travel a bit maybe..an inch, and then build pressure from there.

As I said before Justin, I would bleed the fronts for sure. No pumping, but hold pressure on the brakes (wtf, open first Joop? To each their own I suppose) then crack the line and stop the line before the pedal hit the floor. If open when pedal is idle there is a remote possibility that air can come back in.


HOWEVER. The pedal is not spongy. It just has a long throw, then locks the rears.

I say it needs a MC. Marlin 1" bore $130

Good Luck

 

[dove'd85]

Some input:

The rears are getting plenty of power. In fact, they are locking up on braking.

What is weird, is that the pedal travels about half the throw, then grabs hard. Normally (as far as normal goes. haha) it should travel a bit maybe..an inch, and then build pressure from there.

As I said before Justin, I would bleed the fronts for sure. No pumping, but hold pressure on the brakes (wtf, open first Joop? To each their own I suppose) then crack the line and stop the line before the pedal hit the floor. If open when pedal is idle there is a remote possibility that air can come back in.


HOWEVER. The pedal is not spongy. It just has a long throw, then locks the rears.

I say it needs a MC. Marlin 1" bore $130

Good Luck

everyone has there own way of bleeding brakes.

i personally would gravity bleed the whole system starting at the furthest brake from the mc ect ect.. then i would put a clear line on the bleeder submerge other side of line in brake fluid then open the bleeder then have someone in the car to slowly push the pedal to the floor... close bleeder and repeat...

maybe you have a bad wheel cylinder?

 

[2slow4you]

everyone has there own way of bleeding brakes.

i personally would gravity bleed the whole system starting at the furthest brake from the mc ect ect.. then i would put a clear line on the bleeder submerge other side of line in brake fluid then open the bleeder then have someone in the car to slowly push the pedal to the floor... close bleeder and repeat...

maybe you have a bad wheel cylinder?

front's were bled, we will be gravity bleeding the entire system once it gets nicer out. Both wheel cylinders are in good order.

 

[dove'd85]

this is pretty odd... system worked great before you replaced the rear axles/wheel cylinders/brake parts?

and if the wheel cylinders are good,not frozen seeping/leaking.

you either have air in the system iether caused by a leak in the system, air still in the system from the swap or a bad master cylinder or other brake components such as the factory lsvp:eeek:

after you gravity bleed i would pressure bleed it to. 02