Brake Proportioning Valve Question. (1 Viewer)

[DIGGMAN]

I own a 1975 FJ40 (drum brake early year) ....... so I bought and rebuilt a front axel from a 1978 FJ40 and am in the process of swapping it in...
My existing master cyclinder says its rated for disc brakes...

If i run the 78 front disc setup in the front and drums in the rear, would I need to install Proportioning Valve? And if so..... Where would you suggest I purchase said valve...??

I have looked on this forum and others for threads regarding this question, but am having a tough time finding the right answer...

thanks

 

[msahr]

Nope. I have the ManAFre front disk brakes and factory rear drums, no proportioning valve needed. However, I'm about to start a project to install rear disks...

 

[DIGGMAN]

OK Thanks

...So if I have the 78 front end.. but keep the 75 rear drum, I should be good to go? Hook it up, bleed the lines, and roll?

 

[Fast Eddy]

A stock '76 or '78 would have a non-adjustable proportioning valve that attaches to the bottom two bolts of the master cylinder.

 

[DIGGMAN]

I see...haha.. Now I am confused..

So I do need a proportion valve then?

Where can you buy these.....OEM.....Aftermarket??

 

[Fast Eddy]

I would think that you would want one. They may be available OEM. Ask Beno via PM. Aftermarket would be an adjustable one from somewhere like Summit. I'm not a fan, since there's a perfectly good OEM part. If it's not available new, get a used one from the classifieds and clean it up.

 

[DSRTRDR]

OK Thanks

...So if I have the 78 front end.. but keep the 75 rear drum, I should be good to go? Hook it up, bleed the lines, and roll?

you need to remove the residual valve from the front circuit of the master cylinder - it's behind that big copper hex nut - then you bleed the brakes, ready to roll

when you convert the rear to disk, then you will need a proportioning valve, and it needs to be adjustable

 

[bikersmurf]

Yes. I've got a July 74. Removed residual valve, installed 40 front knuckles and discs, went for a drive. Rears locked up any time I stepped on them medium to hard.

Yes, you'll need the residual valve. Stock will work if you've got rear drums.

Get an adjustable one if you plan on installing rear discs in the future... You'll need the adjustment. I've got a Willwood one that I've been using for 18 years... But others also work.
The adjustable one will also work with rear drums.

 

[Fast Eddy]

Yes, you'll need the residual valve. Stock will work if you've got rear drums.

I'm sure he meant proportioning valve here.

FWIW, I have Toyota rear disc brakes from an 80 series and I run the stock 40-series proportioning valve. It works pretty well. I might lighten the spring a little if I ever take it apart.

 

[DIGGMAN]

Thank you all for you help