Dual diaphragm brake booster on a Wagoneer, how is it?

Stock FSJ Tech Area
Post Reply
User avatar

Topic author
Cataldo
Posts: 287
Joined: Mon Mar 30, 2015 8:13 am
Location: San Bernardino, California

Dual diaphragm brake booster on a Wagoneer, how is it?

Post by Cataldo »

Well I need to replace my brake booster on the '75 Wagoneer. I have heard of running a dual diaphragm booster off of a j20 I believe.

It is a bolt on deal correct?

How does the pedal feel? I do not want overly boosted brakes or touchy brakes by any means. I do tow with the Wagoneer so brake force is important but honestly with my dead booster the brakes are still pretty good. Haha.

Should I go with a dual or stick with a stock single booster?

Thanks
Jay

1975 Jeep Wagoneer: 350 SBC, TH400, Q/T, D44's 3.54:1's. Hell Creek 4" lift with BFG KO2 33x10.5s.

1988 Jeep Wrangler: 305 SBC, TBI, 700r4, NP231c with SYE, 9" w/ Detroit and 4.11:1, 5.25" of lift, 31's. Done up as a Jurassic Park Jeep (Her's)

1973 Chevy Camaro: Vortec 350, 200-4r, GM 8.5 3.23's. 12.4 @ 108mph.

1965 Ford Mustang: Aluminum Headed 347, c4, 3.00:1 gears, High 12's (Her's).



Looking for 1 good factory Kidney Bean Mag in Southern California for use as a matching spare
User avatar

REDONE
Posts: 2678
Joined: Tue Sep 13, 2011 5:48 pm
Location: Lakewood and Bailey, CO

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by REDONE »

I'm pretty sure that the Grand Wags (at least the final edition GWs) came with the dual diaphragm boosters, so I think it's worth swapping over.
79 J-10 (Honcho Mucho) KE0LSU
304/Performance Fuel Injection TBI/MTA1/SP2P/Magnum rockers
T18/D20/D44s&4.10s/33" Mud Claws
Grizzly Locker Rear
4" front spring drop, 5" rear shackle flip
Chevy style HEI (ECM controlled)
Dolphin "Shark" gauges in a fancy homemade oak bezel
3/4 resto, rotting faster than I've been fixing it.

will e
Posts: 5097
Joined: Sat Aug 18, 2012 8:21 am

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by will e »

Go with the dual. I did with my Cherokee when the booster went out. Pedal is fine. It was bolt in. A bit longer than single but you can move the MC carefully. No draining or bleeding of the brakes required.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

will e
Posts: 5097
Joined: Sat Aug 18, 2012 8:21 am

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by will e »

Here is a thread with part numbers:

http://www.fsjnetwork.com/forum/viewtop ... ake#p97947
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge
User avatar

Topic author
Cataldo
Posts: 287
Joined: Mon Mar 30, 2015 8:13 am
Location: San Bernardino, California

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by Cataldo »

OK, So I have figured out that there are two different dual diaphragm boosters
1987:
http://www.oreillyauto.com/site/c/searc ... vi=1182350
http://www.oreillyauto.com/site/c/detai ... &ppt=C0066

and 1975 J20
http://www.oreillyauto.com/site/c/detai ... &ppt=C0066


I would imagine the one from a 1975 J20 would be correct, with the correct rod length and such, am I mistaken?

Does anyone regret doing the dual diaphragm booster swap?
Jay

1975 Jeep Wagoneer: 350 SBC, TH400, Q/T, D44's 3.54:1's. Hell Creek 4" lift with BFG KO2 33x10.5s.

1988 Jeep Wrangler: 305 SBC, TBI, 700r4, NP231c with SYE, 9" w/ Detroit and 4.11:1, 5.25" of lift, 31's. Done up as a Jurassic Park Jeep (Her's)

1973 Chevy Camaro: Vortec 350, 200-4r, GM 8.5 3.23's. 12.4 @ 108mph.

1965 Ford Mustang: Aluminum Headed 347, c4, 3.00:1 gears, High 12's (Her's).



Looking for 1 good factory Kidney Bean Mag in Southern California for use as a matching spare
User avatar

Topic author
Cataldo
Posts: 287
Joined: Mon Mar 30, 2015 8:13 am
Location: San Bernardino, California

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by Cataldo »

Thank You, that answers my questions nicely. haha.
Jay

1975 Jeep Wagoneer: 350 SBC, TH400, Q/T, D44's 3.54:1's. Hell Creek 4" lift with BFG KO2 33x10.5s.

1988 Jeep Wrangler: 305 SBC, TBI, 700r4, NP231c with SYE, 9" w/ Detroit and 4.11:1, 5.25" of lift, 31's. Done up as a Jurassic Park Jeep (Her's)

1973 Chevy Camaro: Vortec 350, 200-4r, GM 8.5 3.23's. 12.4 @ 108mph.

1965 Ford Mustang: Aluminum Headed 347, c4, 3.00:1 gears, High 12's (Her's).



Looking for 1 good factory Kidney Bean Mag in Southern California for use as a matching spare

Nikkormat
Posts: 3623
Joined: Sun Jun 29, 2014 11:45 pm
Location: Salt Lake City

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by Nikkormat »

To keep your current master cylinder use the 75 J20 booster.

To upgrade to the more modern MC use the 87 Gwag booster.

Don't buy a "Loaded" booster. If the MC or the Booster fails you'll have to warranty both at the same time. Swapping a MC and booster intead of just a MC in a parking lot on a road trip sucks.
Gabe, "reformed" Jeep hoarder.
User avatar

derf
Posts: 1403
Joined: Mon Jun 04, 2012 9:10 am
Location: Littleton, CO
Contact:

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by derf »

Side question related to upgrading brake components.

If you switch to disc brakes in the rear, it's a good idea to have a disc brake master cylinder.

I'm looking at the booster swap but what's a good master cylinder to bolt up in place of the factory disc/drum cylinder?
W0JPR

Check out my gear ratio calculator

If you can't fix it with a hammer or duct tape you have an electrical problem.

Nikkormat
Posts: 3623
Joined: Sun Jun 29, 2014 11:45 pm
Location: Salt Lake City

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by Nikkormat »

ghinmi posted a while back about using a late model Chevy truck master with the stock dual diaphragm booster. I'll see if I can dig some info up.
Gabe, "reformed" Jeep hoarder.

Nikkormat
Posts: 3623
Joined: Sun Jun 29, 2014 11:45 pm
Location: Salt Lake City

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by Nikkormat »

Gabe, "reformed" Jeep hoarder.
User avatar

Dr. Marneaus
Posts: 1718
Joined: Fri Oct 05, 2012 10:04 am
Location: Reno, NV

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by Dr. Marneaus »

I have the j20 one in my wagoneer. Works well from what I can tell. I was weirded out initially because coming from drum/drum where the pedal only moved like an inch and required both feet to do that. The j20 booster allows me to damn near press the pedal to the floor with 1 foot with ease. There's significantly more movement involved, however, to achieve the same braking result, than with my drum/drum setup.

For you, it'd be direct bolt in, for me, i had to change a whole ton of stuff.
Well it ain't just the smoke and the traffic jam that makes me the bitter fool I am But this four-wheel buggy is A-dollaring me to death.
For gas and oils and fluids and grease, And wires and tires and anti freeze....And them accessories, Well honey, that's something else.
User avatar

Dusty
Posts: 486
Joined: Wed Apr 18, 2012 11:41 pm

Re: Dual diaphragm brake booster on a Wagoneer, how is it?

Post by Dusty »

derf wrote:Side question related to upgrading brake components.

If you switch to disc brakes in the rear, it's a good idea to have a disc brake master cylinder.

I'm looking at the booster swap but what's a good master cylinder to bolt up in place of the factory disc/drum cylinder?
Just make sure you get a Disc/Disc Prop Valve is all.
I am buying everything now from Inlinetube.com. NO MORE FSJ SPECIALTY SITES!!!!
If God is your co-pilot, you need to switch seats!
Post Reply