Proportioning valve delete for rear disks (1 Viewer)

[cruisedeisel]

Ok, So I have a BJ60 I just upgraded to a rear 80 series disk brake axle. I was wondering if anybody just bypassed the proportioning valve thats attached right to the master cylinder under the hood?

I have an upgraded T-100 master cylinder with a single reservoir.

 

[LAMBCRUSHER]

IIRC when I put my fzj80 rear under my fj55, I ended up using the stock booster and prop valve off a 94 4runner, and a stock fj60 master. I did NOT remove any residual valves or mess with the prop valve at all and the thing stops, like, NOW. HTH

 

[cruisedeisel]

Well my truck is lacking on at least 50% Of its braking power. Like I said. t-100 master/stock booster/stock prop valve and rear disks.

 

[LAMBCRUSHER]

I'd run it, but pay attention to heat build up in the rear...there could be a valve in the t100 master, but maybe not...IIUC, the residual pressure valve is the thing you need to watch out for. some guys get the adjustable prop valve, but as I said, I don't and it seems fine...you just need to make sure that there isn't excess pressure building due to a booster to master rod adjustment or due to a residual pressure valve holding the rear circuit...

 

[LAMBCRUSHER]

BJ60...what kind of vacuum are you running to your booster?

 

[too tall]

I would imagine the vacuum pump on the alternator. Maybe you should try an 80 series master? 1993 non abs is the correct one.

 

[cruisedeisel]

Thanks guys! I am leaning towards the 80 series master.

 

[cruisedeisel]

So absolutely no one on here has just bypassed the proportioning valve? (rusted part under the master cylinder) Just bypass it directly from the master to front and master to rear?

 

[cruisedeisel]

BJ60...what kind of vacuum are you running to your booster?

Yes I am just running the stock bj60 vacuum pump on the back of the alternator. I do have vacuum pressure at the master but I havn't tested it yet?

 

[LAMBCRUSHER]

If your vacuum is low, your brakes will feel weak... does it stop when you lay on em?

 

[Tapage]

If your vacuum is low, your brakes will feel weak... does it stop when you lay on em?

low vacuum = no boost = hard pedal ..

but if you replace your master you should keep in the ecuation / consideration the differences in pressure / flow with the new components ( piston / calipers size )

I did by pass all in my setup ( rear eldo calipers ) and ended with a wilwood proportioning valve after all ..

 

[cruisedeisel]

I have to push extremely hard on the pedal to stop fast.

 

[stevebradford]

My rear drums were barley working so I took the proportioning valve apart and cleaned the rust and buildup out it. Fixed it right up!

This thread is about a 40 similar but simpler might find some relevant information.

Proportioning Valve photos Disassembled

 

[cruisedeisel]

My rear drums were barley working so I took the proportioning valve apart and cleaned the rust and buildup out it. Fixed it right up!

This thread is about a 40 similar but simpler might find some relevant information.

Proportioning Valve photos Disassembled

Thanks for the link. A quick good read. Im sure I can clean it out but I think I have to remove it entirely.

 

[Willard]

You may need one it will depend on the setup.
Some will work fine if the front and rear setups are matched including the master.
Otherwise ditch the 60 valve and swap to an adjustable one.

When I redid my muscle car I switch to 4 wheel disks and my kit came with an adjustable valve. I tried it without....no go.

You will know if all is working when your rear brake do not lockup before the front.