71 Brake pedal switch

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loganobrien121
Posts: 165
Joined: Thu Sep 29, 2016 12:31 pm

71 Brake pedal switch

Post by loganobrien121 »

Hey guys,

My brake switch died so I need to swap it out. Been trying to find the thing but the under dash wiring is like a dangling tumbleweed of misery so I’m having a hard time finding my way. Wanted to know if any of you guys had a picture or knew offhand where the pedal switch is so I could pinpoint it through the knot. I’m assuming it’s right at the top of the pedal assembly? But I’m not seeing anything.

Thanks. I hate wiring that’s gone through many POs. :banghead:
"Betty Blue"
'71 Wag
Buick 350/TH400/D20

"The Bride of Frankenstein"
Green and some uh rust... color...
'73 Wagoneer.
360/TH400

letank
Posts: 4010
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

Re: 71 Brake pedal switch

Post by letank »

on 74, it is a black wire on top of the cylinder looking switch, sometimes when it stops working is is rust that has built up over the contact circle that has a very very very narrow lip for the contact.
when mine stopped working, I had to repeat a few passes with a nail file to remove the rust

the shinny piece on the lower right in the pedal mechanism

Image
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)

Topic author
loganobrien121
Posts: 165
Joined: Thu Sep 29, 2016 12:31 pm

Re: 71 Brake pedal switch

Post by loganobrien121 »

Ohhhh so it’s on the E brake housing? I expected it to be a pressure switch on the pedal but I’ll take a look. Thanks!
"Betty Blue"
'71 Wag
Buick 350/TH400/D20

"The Bride of Frankenstein"
Green and some uh rust... color...
'73 Wagoneer.
360/TH400
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tgreese
Posts: 7118
Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: 71 Brake pedal switch

Post by tgreese »

Does the OP want info about the parking brake? That's what's in the picture.

'71 should be a hydraulic pressure switch. Jeep PN 931216 https://www.ebay.com/itm/KAISER-JEEP-BR ... 2604546378 It will not be under the dash. If it's not on the master cylinder, look for a hydraulic fitting (a brass block) down on the frame rail, in the brake tubing.

'73 changes to a mechanical switch on the brake pedal, under the dash.

This will help you: https://www.rockauto.com/en/moreinfo.ph ... 90&jsn=371
There is a '62-73 J-series parts manual here http://oljeep.com/edge_parts_man.html Item 3.333-1. If you have difficulty finding items, post up a question.
Last edited by tgreese on Sat Dec 01, 2018 4:27 pm, edited 2 times in total.
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lkmarsh
Posts: 211
Joined: Mon Jun 11, 2012 8:35 pm
Location: Modesto CA

Re: 71 Brake pedal switch

Post by lkmarsh »

LeTank is pointing out the parking brake switch. Are you referring the the brake pedal switch? On my 69 it is
a hydraulic switch mounted to the bottom of the master cylinder. Mine went bad and leaked out fluid and let in air.
Coming back from Tahoe was a memorable experience not to be repeated. Made a bracket for a standard GM brake
pedal switch and plugged the hole under the master cylinder. Terrible design work. Don't know when, if ever,
the factory changed design to fix that mistake. Does your Wag still have all the fuses hanging off the ignition switch?
Lyle
69 1414x Buick350/Th400/D20
PDB, HEI, relays, rallyes, rhino, rust...
73 Wagoneer parts donor

Topic author
loganobrien121
Posts: 165
Joined: Thu Sep 29, 2016 12:31 pm

Re: 71 Brake pedal switch

Post by loganobrien121 »

thanks for the replies! Sorry, been super busy so haven’t had a chance to crack into it yet. But that’s super helpful. There’s a switch on the MC so that makes sense why I wasn’t seeing anything under the dash.

Wow so that doesn’t seem like the best of designs... if I put in a new hydraulic switch is it prone to failure or are they mostly fine and only fail after 50 years? Wondering if it’s worth swapping to the GM style or if I should just keep it stock.
"Betty Blue"
'71 Wag
Buick 350/TH400/D20

"The Bride of Frankenstein"
Green and some uh rust... color...
'73 Wagoneer.
360/TH400
User avatar

lkmarsh
Posts: 211
Joined: Mon Jun 11, 2012 8:35 pm
Location: Modesto CA

Re: 71 Brake pedal switch

Post by lkmarsh »

If I had to do it again I would still ditch the hydraulic switch for the GM style pedal switch.
If you plan to upgrade the mc you will need to do this anyway. Changing the brake light switch
when it goes bad is much easier if you don't have to bleed the mc afterward.
Lyle
69 1414x Buick350/Th400/D20
PDB, HEI, relays, rallyes, rhino, rust...
73 Wagoneer parts donor
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