Dual Diaphram on a First Gen

[Big Mac]

I just picked up a master and booster and clutch master from a 90s 4runner for 45 bucks from the wrecker.

Booster is dual diaphram and the master is 1". Clutch master looks new, both are Aisins.

I understand that there are some problems with putting the dual diaphrams on first gens.


I was thinking that, if I could use the spacer that comes on the stock booster with the new booster, I can move it away from the steering shaft. But the studs are too short and the push rod deal would have to be lengthened. Are the studs removable?

Has anyone done this swap successfully?

[OOP'S]

Ist gen runner.

http://home.4x4wire.com/erik/4runner/brakes/

[Big Mac]

Sorry, I should have been more clear. I meant first gen pickup. (79-83) I've read up on the second gen pickups (and first gen runners) and it appears they have more room.

[Big Mac]

So no one in the wide world of pirate4x4 is running a dual diaphram booster in a first gen pickup?

Does anyone know if the studs are removable from the back boosters?

How far in can you dent the boosters without any ill effects?

I'd really like to run this thing in my 83.

[thewizard182]

Be the first!

[OregonYO]

So how close are you to doing this?
I put a 2004 envoy master cylinder on my stock booster and my pedal feels good w/ rear disc and stock front.
How much bigger diameter is the dual?
I was planning on this swap sometime in the future.

[SeaBass44]

Originally Posted by thewizard182

Be the first!

no shit, stop waiting to be spoon fed

[Toyota_Dave]

Actually, I did it very successfully. I picked up a dual diaphram booster/1 inch master from the junk yard that was on a early 90's Toyota dually 2 wheel drive. It had the same spacer that was on my 83. I had to make an additional 1/4 spacer for it to clear the steering shaft, but it fit just fine.

[Toyota_Dave]

I'll see what I can do when I get home tonight. It's already installed so you won't be able to see the additional spacer I put on. It's just made out of some 1/4" aluminum plate that I had and I just cut it to match the existing spacer.

By the way, I think that the studs on my diaphram must have been a little longer than what is normal on other diaphrams. Also, this booster came off of a dually cab/chassis so I'm assuming it may be a bit bigger than a normal 2WD booster. I know it was bigger that the one that came off of the 83. Until I get home tonight, here's about the best pic I have of the booster.

[Big Mac]

Here's a comparison shot of my stock booster and the dual booster I got.

As you can see, the studs are much longer on the stock 83 booster because of the aluminum spacer that's used. I was hoping i could just switch the studs from one booster to the other. But, since they are welded on, that might not work.


I put the stock spacer on the new booster, you can just see the studs poking through the spacer here, so they aren't long enough.

I was thinking of making my own spacer out of 2 pieces of plate and a chunk of tube in the middle.

[Toyota_Dave]

Yep, I'd say the booster I picked up definitely had longer studs on it. I was able to put the original spacer plus the 1/4" space and still had plenty of thread inside the cab. Here's a few more shot of mine.

[Toyota_Dave]

No, the steering shaft is still in the stock location. I do have a 1 inch body lift on the truck to give me some clearance for the 4.3 that I have in it though. That could have put the shaft at a bit of a different angle coming out of the firewall possibly. Now I did have clearance issues with the steering shaft when I first test fit it, but that's why I did the additional 1/4" spacer in there.

When I did this I had no idea there were issues with putting a dual diaphram in a 1st gen truck. I may have just got lucky when I was scrounging the junk yard looking for one. I'll have to check to see if there is a part number on the diaphram so I can post it up. By the way, I had no issues with the push rod going in to the brake pedal either.

[Big Mac]

I did some crude paint sketches of what my idea is for the spacer.

The push rod will have to be longer, so I thought this up.


I thought about just welding a rod onto the existing one to make it longer, but the heat might damage somthing inside the booster.

[SeaBass44]

what year did the DD come out?
my 88 is single

[Toyota_Dave]

Not sure of the exact year, but I just checked my son's 89 and it has a dual diaphram in it. It's a V6 4x4 by the way.

[Toyota_Dave]

Well, I checked the booster and it has no part number on it that I can tell. I have a buddy whose the parts manager at a local Toyota dealership here in town so I'll check with him to see if he can help me out on getting a part number for this thing.

[robrub00]

i think all v6 are dd and the 22rte's were dd maybe others

[Toyota_Dave]

Just a quick update on the truck that I got the dual diaphram booster off of for my 83. It came off of a 1993 2WD Toyota Cab/Chassis Super LWB with a 3.0 V6. The VIN number on the truck was JT5VN94T8P0030532. Hope this helps out.

Also, if anyone is wondering, this booster had the exact same aluminum spacer that is found on the 1st gen trucks. This thing bolted right up. I did have to add an additional 1/4" spacer so the larger booster would clear the steering u-joint.

[Chass]

For whatever its worth, we put a V6 master on a stock 83 diaphram and it works great. I don't think the bigger booster was necessary with they D44 axles that went under the truck. I think with toy axles you'd be just fine.

Chass
ct

[Toyota_Dave]

Originally Posted by 4RnrRick

2wd or 4wd? I'm assuming 4wd, but you didn't list it above.

Oops, I forgot to put that. I fixed it. By the way, it was a 2WD.

[TroyToy]

thanks guys

I needed this one....way too go

[Erick561]

that engine in that first gen truck isn't the same as stock tho. Prolly doesn't make a difference with the steer.