BJ74 brake master cylinder

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Did you remove the LSPV as well?
 
elkaholic said:
Did you remove the LSPV as well?
Click to expand...
Sam, you have known me long enough to know that any technical question that does not use the phrase do-dad or do-hickey is above my pay grade. As far as I know LSPV could be a sexually transmitted disease. :)
 
Hmmm, the proportioning valve. The truck came with a 2 inch lift. Should the valve have been re-located?
Is it possible to check for proper function?
 
1978HJ45 said:
Sam, you have known me long enough to know that any technical question that does not use the phrase do-dad or do-hickey is above my pay grade. As far as I know LSPV could be a sexually transmitted disease. :)
Click to expand...
OK.

Was the do-hiicky that the brake lines run to over the rear axle that has a rod do-dad coming down to the rear axle removed. This would be right inboard from where the do-hickey where you put diesel in the 74 is, but under the body do-dad. :grinpimp:
 
I'll ask Rob. Robs is my do-hickey, do-dad specialist. I'm just the knuckle head that puts the key in the ignition. :)
 
:rimshot:
 
I spoke to the guys in White Post, Virginia. If all goes well, I'll be able to drive over there (in my F150) and hang around while they re-sleeve the original MC.
 
jblueridge said:
Hmmm, the proportioning valve. The truck came with a 2 inch lift. Should the valve have been re-located?
Is it possible to check for proper function?
Click to expand...

I have had 3 x 70 series with 2 inch lifts and none of them needed the LSPV valve altered. I guess the easiest way to observe it in action is to compress the suspension . I think there are some specs in the FSM
 
Need is the wrong term. With a suspension lift and no adjusment to the LSPV, you simply get less rear braking power for a given pedal effort and an effective shift of brake bias to the front. Eg. you'd get front lock-up at a relatively lower rate of deceleration than with a correctly adjusted LSPV.
 
So if I am understanding correctly.... and yes I realize this thread is old.... my recent addition of an OME 50mm (2") lift requires adjustment of this LSPV? How would one do that?

I am actually searching brake issues since my next project is new pads, adjusters, shoes, drums and rotors all around. I will be checking the lines for corrosion so reading up on the issues people have had. I have noticed recently after doing the suspension upgrade, that the brakes seem a lot weaker (reading this thread has me looking at the LSPV) So would like to know how to adjust this LSPV.

Thanks and Cheers!
 
I ended by using the MC from an older 80 series cruiser as well as the larger brake calipers and pads. I put on new rotors, drums and shoes also. I had the vacuum booster rebuilt.
Vastly improved stopping power was the result.
 
jblueridge said:
I ended by using the MC from an older 80 series cruiser as well as the larger brake calipers and pads. I put on new rotors, drums and shoes also. I had the vacuum booster rebuilt.
Vastly improved stopping power was the result.
Click to expand...

Yes I have been concerned about the booster and or the vacuum pump. I have a feeling I am loosing a little there. So will do the shoes, pads, rotors, adjusters (will be nice to have an E brake again) and drums as well as figure out something for the LSPV. Will see how that sorts things and then dig in from there if need be. It is nice to know the 60/62 stuff works since that is all readily available here. Don't like feeling like I am back in PNG and having to wait 6 months for parts to arrive from Japan.
 
I ordered new carbon rotor blades for my vacuum pump. I forgot to add that the booster I used was also from the 80 series: it has dual diaphragms and holds the air better. I plan to pitch and replace all the vacuum lines when I take the vacuum pump apart. Some people have installed vacuum reservoirs with greater volume. If I need it, I might cut the original reservoirs and weld in some spacers to make the cans longer.

I just ran the LSPV to the top of its adjuster travel. Seems okay.
 
jblueridge said:
I ended by using the MC from an older 80 series cruiser as well as the larger brake calipers and pads. I put on new rotors, drums and shoes also. I had the vacuum booster rebuilt.
Vastly improved stopping power was the result.
Click to expand...
This is exactly what I did... For the Master Cylinder specifically I replaced the brake line and created a small adapter for the heat sheild. I have not installed the 80 series booster but it is on my bench in the queue of things...
 
Booster is bigger. I made a trashy looking heat shield that works.
 
Last edited:
Did you have to put any spacers against the fire wall so that it fit the same on the pedal and or the master cylinder?
 
The 80 booster goes in upside down and you need to make a 1inch extension for the booster rod.
1992 4 runner calipers 014.webp
 
You must log in or register to reply here.

Similar threads

M
Brake Master Cylinder
Replies
10
Views
2K
coldtaco
coldtaco
A
1986 BJ74 80 series brake booster upgrade??
Replies
4
Views
452
jblueridge
J
K
BJ74 flare extension ideas
Replies
1
Views
448
janyyc
janyyc
N
New slave cylinder
Replies
9
Views
1K
CardinalFJ60
CardinalFJ60

Users who are viewing this thread

Total: 1 (members: 0, guests: 1)

Share this page

Back
Top Bottom