Bleeding master cylinder?

Lost a brake line this past Sunday - hit the brakes hard to miss a deer and felt the pedal get weird and squishy afterwards. Brake fluid visibly leaking from the area where the line failed - this was one of the lines that goes from the master cylinder to a junction point basically under the driver's door, where it meets up with the long lines to the back.

I was originally just going to fab up a shorter line from nicopp tubing, but realized there were some other iffy-looking parts on the 2 lines from the MC to the back, so instead we made replacements and installed them. Bled the brakes, pedal feels great when the truck is turned off but when you turn it on, the pedal just goes to the floor.

Realized that we had not bled the MC properly (and it had run dry, so we need to) -- but how? Factory service manual says to disconnect the lines, then hit the pedal 3-4 times and then hold gloved fingers over the ports. But how do I prevent the fluid from immediately running out if I disconnect the lines? I must be missing something big here. Anyone?

 

I would recommend getting one of these kits. The plastic fittings go on the ports and you can run a hose back into the reservoir and bleed it by just pressing on the brakes from inside the cab. It saves a lot of the mess. After the air is bled from the MC you can reconnect the lines and bleed it as normal at each corner of the vehicle. If you have a proportioning valve don't forget to bleed that too and make sure you adjust your drum brakes after. I've seen the squishy pedal be caused by out of adjustment drum brakes

 

$9 Enhon Master Cylinder Bleeder Kit Replacement for 13911, 22 In Clear Hose, Clip, SAE and Metric Fittings Universal Fit, Complete Brake Bleeder Kit with PTFE Tape

https://www.amazon.com/Enhon-Cylind...1&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY

 

That looks like a big help, I've ordered one of the ones with two m10x1.0 fittings (I think 14151 is the number?) - anything else I can do to get the truck back on the road in the meantime?

 

Power bleeder

 

Pardon my ignorance, but is this setup and kit applicable only if your doing a manual bleed by pumping the brake pedal?

 

fill master cylinder
put someone in the drivers seat
start at passengers rear corner
pump pump pump - hold
bleed
pump pump pump - hold
bleed
using clear tubing into an old clear water bottle, bleed till you see clear new fluid
move to the drivers rear corner
repeat
move to the proportioning valve under the bed
repeat
move to passengers front
repeat
move to drivers front
repeat
buy a big bottle of fluid, and keep the master cylinder topped off
this should flush the whole system, its effective and gets you going later today if you can find help to put in the seat to pump pump hold

 

No worries, power bleeder works like filling a balloon, the balloon is the mc. The air pushes the fluid through the lines and is bled out at each bleeder valve (tundra has 5) . You won’t have to bench bleed this way. For no money, follow others advice/process

 

i have a snap on power bleeder that uses shop air
i have a snap on power bleeder that you pump up like a pump up sprayer
i have seen videos of the cap that replaces the master cylinder cap with a regulator and shop air and compresses the fluid on top of the master cylinder and pushes it out the lines so you can one-man bleed

if you dont already have those and need to drive TODAY, better put somebody in the seat.
if you have time, order the tools and do it yourself.

 

Just make sure you tell whoever is doing the PUMP PUMP PUMP part, don't mash the pedal all the way to the floor to avoid potentially blowing out any seals. Or physically put a board on the floor to prevent them from mashing pedal to the floor.

Also, start at the prop valve, bleed, THEN go to the passenger rear. Trust me. Air tends to get trapped at the LSPV (load sensing prop valve, on inside of frame, above driver side wheel backing plate) because it's the highest rearward point of the system. Failing to bleed, even the tiniest air bubble in there, is going to leave you with lackluster pedal function.

 

I had my son in the driver's seat pushing the pedal, so a 2nd person isn't a problem. But it sounds like the master cylinder has to be bled independently of everything else - at least according to the factory service manual.

Does the power bleeder also take care of this step, or do I still need to do it separately? I have one, but I don't have the Toyota adapter for it.

 

When i did mine, i use the power bleeder to get clear fluid out of each corner and then put my ole lady in the driver seat for a few pump pump pump holds. I moved the seat back so when her leg was fully extended she couldnt push to the floor and put a block of wood on the floor, didnt want any chances. My truck stops like a dream after i changed everything around and bled everything.

 

A power bleeder tool should eliminate the need for bench bleeding. Bench bleeding just saves time getting air out the mc, so it’s full of fluid. The power bleeder pushes all the air right out. When pb (power bleed) abs system, turn the key to acc to allow the abs pump to move fluid through