Can you Help Identify this Caliper?

While attempting to loosen front driver side bleeder valve screw on my bronco, I managed to twisted it off. I was being as careful as possible, but I guess it just was stuck enough that it twisted off instead.

One of the previous owners of this bronco (1970) installed disc brakes on the front (I'm not a bronco guru, and am assuming disc brakes were not an option on these?).

I need some help determining where these caliper came from in order to get a replacement. I can't see any distinct part number on it. I'm not a "car guy" to know by look at it either. So I turn to you experts for guidance. I took some photos. Hopefully they are good enough for you to help me. In one you can make out what seems to be the numbers "499" but I'm not certain.

Also, does one have options as to what sort of calipers would fit the current set up? If I can get better replacements for these single piston calipers, I would be open to it.

Thanks in advance!


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Those are GM calipers. For replacement lookup '74 Blazer 4x4.

2x.

everyday gm caliper, can get those anywhere.

Viperwolf1 said:

Those are GM calipers. For replacement lookup '74 Blazer 4x4.

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impressive! Thanks guys.

btw, does any one have a handy link to a diagram of stock brake lines for an EB? I've been googling but not quite finding what I'm looking for.

my simple project of "flush the brake system and replace with new fluid" is turning into a monster task after braking the bleeder valve:

• get new caliper
• hey it is cheep enough so lets replace both sides at the same time
• Oh CRAP! the previous owner hooked up brakes lines from MC to front and rear brakes backwards
• so lets replace those too
• hmm... looks like from the proportioning (I think that's what it is?) valve only one soft line goes down to the axle and then splits to each disc
• the valve looks really old and gunky so maybe reaplce it too.

Unless someone changed it out for a real proportioning valve, the stock brass H-block is just a distribution block with a simple pistion between the two circuits that pushes a switch if either end develops a leak.
That's what that little "BRAKE" light on the dash is wired to.
So I'm guessing gunky isn't so bad. They rarely work properly anyway, but don't often cause trouble with brake performance, that I'm aware of.

If it's a real proportioning valve, I don't know if those go bad or not. Doubt it, but it may have a small pin that you have to pull to properly bleed the brakes. So look for one of those to make sure.

Can you tell what master cylinder you have? Stock? Bronco disc type? Something else? Some of the GM masters that people use have the same size reservoir front and rear. Most of the stock-ish types from Ford use a larger rear reservoir (for the front brakes) and a smaller front one (feeds the rear brakes.).
If you're not sure, post up some more pics.

Paul

DirtDonk said:

Unless someone changed it out for a real proportioning valve, the stock brass H-block is just a distribution block with a simple pistion between the two circuits that pushes a switch if either end develops a leak. That's what that little "BRAKE" light on the dash is wired to.

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It is actually a combination valve (I'm learning this stuff as I go along), which is a combination of metering valve, proportioning valve and the pressure differential switch (as you mentioned for the brake light in the dash).

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This picture doesn't quite show it, but only one of the front outlets is being used. Is there any good reason to only use one of the two front outlets instead of both? My friend found an image of a similar combination valve online (I can't find the link ATM) but it suggested using only one outlet for 4x4 trucks. We can't figure out why that would be.

DirtDonk said:

Can you tell what master cylinder you have? Stock? Bronco disc type? Something else? Some of the GM masters that people use have the same size reservoir front and rear. Most of the stock-ish types from Ford use a larger rear reservoir (for the front brakes) and a smaller front one (feeds the rear brakes.).
If you're not sure, post up some more pics.

Paul

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I am not sure. It is definitely not stock as it is a drum/disc MC. I think I have to take it off the booster to see if there are any part numbers underneath. A friend that's been helping me with this thinks this (Dorman M39531) may be a close enough MC, but not sure. Here are pics of mine:

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Off the booster I can see this number "13088". I was hoping to be able to google that number and figure out exactly what MC I can get that would fit exactly to the existing booster, but that's proving to be a tough task.




Thanks Paul and everyone for your replies and info!

--patrick

Not sure from numbers, but it's a "stock-type" master for power brake applications. Power assist masters had the ports facing the inside of the engine compartment and non-power masters had the ports facing outward.. Typical Ford (Bendix?) looking thing.

And that valve you show a picture of is definitely (at least as definitely as I can tell) a proportioning valve. Yes, a combination valve, but I've heard our simple H-blocks called combo valves too, so I thought I'd make the differentiation here.
Yours is a prop valve with the little pull-pin thingy that you have to either push OR pull, depending on what the original application was. Looks like it's been there for a long time and might (I don't know for sure though) have been an original '76/'77 Bronco type. If so, I think you push the pin to bleed.
Others more familiar with prop valves will know.

Paul

And I believe you and your friend are correct. The unused port was probably for a car application where they ran hard-line to the other side as well. As you've seen, the 4wd Ford trucks use a single down-tube with flexible hose to the axle and from there, the hard-line goes to the passenger side.

That's my guess anyway. And I'm sticking to it.

Paul