Brake bleeding

Hey guys.

So in my rebuild I've replaced about 90% of my brake system.

It has:

90% new hardlines
No ABS
Donor LSPV
Tundra front calibers
Original MC
Original rear cylinders
New pads/shoes/rotors/drums

I tried bleeding the brakes and was getting nowhere. After google-fuing I realized I didn't bleed the master cylinder first. But its back in the truck already. I'll try bleeding it with the thumb plug method or with tubes looped back into it as I saw done on a 1AAuto video.

I watched Timmah's video on bleeding a 4Runner and he said you have to have the key on to activate the booster in order to bleed it. DOES THIS ALSO APPLY TO TACOMAS?

I need to know before wasting more of my time, cuz I'm not ready to turn it on yet.

Also I'm using the compressed air bleeder tool.

 

I bled mine with the loops back into the reservoir, don’t recall anything about having to have the key on. Mine is non abs

 

Take your mc off and bleed it on the bench. Takes very little time and then you know it’s bled.

Does your lspv have a bleeder? I removed mine so I can’t remember. If it does, bleed to there. And then bleed to the rear brakes. You can also take the arm off of the axle and tie it up so the valve has less restriction while you’re bleeding.

Haven’t watched the video, but your booster is just a force assistance and doesn’t actually move the fluid. I can’t think of an reason you’d need to “activate” the booster. You’d need the vehicle running too since the booster works off of vacuum.

hope this helps. It took me a long time to get my brakes bled after putting in new hard lines and doing the tundra upgrade. Lots of places for air to hide

 

Always bleed with the vehicle on. You can loop the lines on the MC into the reservoir and bleed it that way. After that's done, have someone press the brake pedal 5 times, hold it the 5th time, then bleed the LSPV, do that 3 times, then do a reverse Z pattern starting with the rear passenger. Do each brake 3 times for best results.

 

Can you explain to me why you’d want the vehicle on? I’m having a hard time wrapping my head around it.

 

That's the way I've always done it and it always works. No further explanation needed.

 

WAG. Maybe it’s easier to pump the brakes with the vacuum booster.

 

Pretty easy to press with air in the lines too tho

 

Back to the original issue. When I upgraded the MC, I tried to evacuate the air (out) by cracking the lines by the MC, pressed the brake pedal, held the pedal, tightened the brake line, repeated 4-5 times. Semi worked. Ended up just bleeding the old fashioned way.

Sequoia MC in Tacoma

 

I appreciate the feedback yall.

 

I had a 90’s f150 for a while that I wasn’t able to bleed the clutch after putting in a new clutch. I ended up bleeding it from the slave cylinder back to the master using a mity vac kit. This is also the procedure for A lot of general aviation airplane’s brakes.

 

You can vacuum bleed the master cylinder on the vehicle. No need to remove it from the vehicle or disconnect the hardlines. Put a vacuum on the reservoir and leave it be for a few hours.

 

Similar issue.....only mine was a reman oem one from napa.....

MC bled just fine on bench.....installed and would not pressurize...

Left everything open over nite to gravity feed.....nothin came out...

Bad MC right out of the box......

.....had to go to nuclear option to get fix that day.......the Zone......

That one bled fine and had truck running in 15min......after messing with the other for two hours.....

 

I need to replace my master cylinder as well.
Talked to local dealership, OEM part (47201-04030) costs over $300.
Gonna go hunt for one at pull a part.

 

I tried to go oem....but saw what happen there....
scotty says the aftermarket ones are fine.....
.....just dont buy reman ones......boy was he right....

Any way still got to keep my old oem one.....I'll just order an oem master rebuild kit for it.....on next mcgeorge order....about $60......

And stick all on a back shelf for a rainy day......

 

Found a used OEM on ebay, unknown mileage.
Never rebuilt one of these, how involved is it?
If I can rebuild my OEM brake booster, maybe I will go that route.

 

Update: brakes bled ok this time. I bled the MC with lengths of tubing looped from the outlets back into the reservoir. Finished the rest of the system like normal.