Express, Savana & G-Series Vans Offered in both a full size van, or a large box truck, the Express is the modern GM workhorse.

Chevrolet Express
Platform: GMT Van

replacing drum brakes with disks - G20

Thread Tools
 
Search this Thread
 
Old Mar 25, 2025 | 7:39 PM
  #1  
rickyralph's Avatar
Thread Starter
CF Junior Member
5 Year Member
 
Joined: Apr 2016
Posts: 70
Likes: 9
Default replacing drum brakes with disks - G20

sorry if this has been beat to death. I assume if it has i'll be quickly pointed into the right direction. But I did a little searching on here and didn't find any info pertaining to the G-series vans -

Mine is a 1990 and I aim staring down the barrel of a rear-brake overhaul. hubs are bad, some pin fell out of one of the drums when opened and now my E-Brake stopped working. Ultimately, if I'm going to re-do them and i think i'd rather spend a little more and scrap the drums altogether. Mostly I would love the increased stopping tightness that disks tend to give and replacing all the mechanized none-sense in the drum is always a top miserable experience for me.

I've looked around online and haven't been able to find many kits that weren't crazy expensive. lots of kits for newer model vans go for reasonable prices but not seeing much for older models like g20s and 1500 series etc. I have watched a few videos of other older trucks swapping out rear brakes and it doesn't seem like a two customized adaptor plates and a set of rotors etc should run over a thousand dollars. but I don't do advanced metal work so what do i know?

There must be some online mom-pop place still spitting these things out for less than exorbitant pricing? Hoping someone on here knows where!
thanks in advance-
e
Reply
Old Mar 25, 2025 | 8:58 PM
  #2  
Triaged's Avatar
CF Pro Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2019
Posts: 623
Likes: 177
Default

My 2015 has a 14-bolt semi floating axle that has been around for many decades and is likely the same as yours. That's the nice thing about GM, their cheapness and reluctance to change. Take a couple of measurements and pictures, go to a you-pull-it yard, and get the backing plates and brake cables you need. Alternatively just get the whole rear end.
Reply
Old Mar 25, 2025 | 9:04 PM
  #3  
Rednucleus's Avatar
CF Addict
10 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2014
Posts: 2,330
Likes: 308
From: Marysville, WA
Default

Would you also need to change out master cylinder components??
Reply
Old Mar 25, 2025 | 9:14 PM
  #4  
Triaged's Avatar
CF Pro Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2019
Posts: 623
Likes: 177
Default

1990 likely doesn't have ABS. You can take apart the combination valve and block off some of it like the hold off valve. Somewhere I've got a picture of a taken apart combo valve. Do you have an aluminum one or brass?
Reply
Old Mar 26, 2025 | 7:22 AM
  #5  
rickyralph's Avatar
Thread Starter
CF Junior Member
5 Year Member
 
Joined: Apr 2016
Posts: 70
Likes: 9
Default

@Triaged - 2015 what? i love the idea of swapping in another compatible rear end from a junker - and yes, there's no ABS on my ride / I am 99% pretty sure it's an aluminum combo. will check at some point today and update if wrong

@Rednucleus - you got me. this post is really the beginning of my research.

Reply
Old Mar 26, 2025 | 9:18 AM
  #6  
Triaged's Avatar
CF Pro Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2019
Posts: 623
Likes: 177
Default

Originally Posted by rickyralph
@Triaged - 2015 what?
express 3500 6.0l... but by then they all the gas were the same. It's really a 3/4 ton axle likely the same as yours. 9.5" 14-SF not 10.5" 14-FF that used to come on a 1-ton

Originally Posted by rickyralph
... I am 99% pretty sure it's an aluminum combo.
I'll have to find my picture on my computer but this post has a good cross section image. I had blocked out both the rear proportioning valve and the front hold off valve then installed an aftermarket adjustable proportioning valve for the rear. That left only the sliding differential pressure switch that turns on the idiot light.
https://www.hotrodders.com/threads/s...epancy.464922/
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
BamaBiggDad
2007 - 2013 (GMT900)
3
Apr 2, 2022 8:11 PM
JIMMYDRIVER1
Express, Savana & G-Series Vans
2
Jun 14, 2017 5:01 PM
camaorkidd 86
Nova & Chevy II
2
Aug 11, 2014 6:58 PM
Mille Racer 69
Silverado, Sierra & Fullsize Pick-ups
3
Dec 8, 2010 8:26 PM
negra07
Tahoe & Suburban
2
Jul 2, 2007 6:12 PM




All times are GMT -5. The time now is 6:20 PM.