Lost my brake pedal on my way to work yesterday. Pulled into a gas station to find my master cylinder almost dry and found a small line leak in the rear above this:



What is this thing? proportioning valve?
The two rear lines go into it, one output (the leaking line) into rubber and a 3-way, then into both cylinders.

I'm hoping I can get the severely rusted brake line out of this thing, but want to know exactly what I'm getting into (price wise) in case this part needs replacement.

95 t100 dlx, 4wd, 3.4l

Thanks for looking.

(ps. The fluid saturation is not that bad, only a small drip off that line, the entire thing is sitting in PB blaster. And: WHAT KIND OF GAS STATION DOESN'T CARRY BRAKE FLUID???)

 

Hey, it must be those Vermont gas stations. No brakes necessary in VT despite all the hills. Anyways, you're right, that is the proportioning valve for the rear brakes. As you put more and more weight into the truck bed, that arm deflects. The more weight in the bed, the more deflection, the more braking power to the rear. You don't need it, but if you eliminate it, you may have issues with the back brakes locking up and such. A lot of people will put in a proportioning valve in the engine right off the master cylinder.

It looks like you have a leaky brake line. Replace that rusty brake line. You can get them at your local parts store (make sure you get double flared metric line) they come in a variety of lengths from 12 inches to multiple feet. If it is that short line that goes into the top and then into the rubber line, that shouldn't be too bad. Make sure you use a flare nut wrench - standard box wrenches tends to just strip those rusty nuts. The brake lines from the auto store will be straight, but you can simply bend them by hand into the desired shape.

 

+OMG!

Thats the rear proportioning valve and you are not saving it. I really do not think you can get those off.

Go to Jegs. com and get yourself a proportioning valve and -3 line and fittings so you can just replace it all. Marlin Crawler has a braided hose to replace the rubber hose which makes life easier. You have to crimp or block off a distribution block under/in the right fenderwell were it bleeds to the front brakes. Thats why you lost all brakes, they feed each other.

 

skypilot, i agree it's ugly, but the threads just may be okay.

That's my hopeful/optimistic thinking because my truck came from Northern VT and everything had/has rust on it. I salvaged lots of parts that looked really bad, but were in decent condition.

 

For the majority of Vermont your right. However, I live in Chittenden county, when the high schools get out, I need brakes.

I figured I could remove this from the system all together. Thing is my trucks a long bed and I drive it empty half the time and fully loaded the the other half.

I'm not sure you can see it but the proportioning valve mount is completely rotted off the frame so the entire thing is held up by that leaking brake line. Could explain the brake shutter I've been experiencing lately if its bouncing around sending different power to the rear brakes.

Good thing is the truck is not my daily driver so I would like to get everything that might be replaced in advanced to limit trips to the parts store. Now I just need to find out if the part is dealer only, available at my local parts store, or available online.

Thanks for you help!

 

I've saved worse looking things, I've also broke better looking. Either way I'd like to have a replacement on hand before I rip that line out.

I took a quick look over at jegs, do they only sell fixed and manual adjusting valves? Looking for an similar, auto adjusting replacement.

Thanks.

 

is it possible to grind off the rust and get some good metal for some welding? The junk yard would probably have some in the yard.. ..doesn't look like NAPA has one. Report back with your fix!!!

 

If I can save the threads, I can probably figure out a new mount. Everything is closed today so I'll have to drive around tomorrow after class for prices. I doubt I can find a salvaged part, haven't seen a T100 in the junk yard around here for years. I think they crushed them all when the price of steel skyrocketed years ago... Anyone know if its the same part on tacos and runners?

 

Its more likely that a 89 to 95 pickup ? 4 runner uses the same part. Tacoma's maybe, but I have never been under one.

 

After unable to find a inexpensive replacement valve I decided to give it a shot. After a few days of soaking the line with homemade acetone-atf penetrating oil, I was able to save the valve with some careful old fashion vice-grip work (the use of flare wrenches for old brake lines in VT is almost non-existent, a comprehensive vice-grip set is my best friend):



As far as the mount, there's really no good metal to fab anything so I had to be creative... Feel free to laugh.


6 250 lb test zip ties. Sure isn't pretty but it works. All sealed up, solid, and bled. Able to lock up the tires without any shudder.

Total cost: $3.63 + some zip ties and brake fluid I had laying around.

and just for fun:


Thanks for the help YT!

 

That is some scary looking rust. Very sad to see.

 

^ You should have seen my 86. Still runs better than 4 year old chryslers.