all i no is this the post office P-30 chassis that had the last year of drums was a 1992 for us and they order weird stuff in DC and they have a hugh rear wheel cylinder! I no there larger then 30! I will get the specs for them asap for you guys we still have a few left in our fleet and i own one as well! Way over kill brakes in the rear! The fronts are dual piston and the rear shoes are 6 X 16! Yea shes got alot of pedal. I had put close to 10,000 pounds in her already and when stopping it's like no big deal at all! But then again the power brakes are hydroboost no anti lock and the master runs 1.5 bore in it as well. So it gets the fluid moving

 

oops, yer right, dyslexia kickin in i guess

 

The 37337 is the United brake part. United IE USA company. the TSW is the economy part to compete with Auto Zone ETC., made in China

 

When the guys at my Napa pulled both grades out they couldn't figure out which box to put them back in they looked so much the same.
I've used the under $15 ones on at least 15 trucks without problem.
My own cheapos have been in for over eight years.

 

Normally I'd say go go "USA", but for a 400% mark-up it's no wonder people go Chinese....

 

Napa sells a self adjuster rebuild kit for $20/wheel. I have to rebuild my whole brake system this weekend (got contaminated fluid so all the seals are destroyed)... I'm going to do the GM upgrade wheel cylinders... might as well get the "self adjuster" rebuild kit and let you know if I see any improvement.

Might get my drums resurfaced while I'm at it... fun fun fun...

 

i just did this mod on my second truck today. man i cant get over how much difference it makes.

 

Before you are going to do any work on the rear brakes do yourself a favor and pickup a spring tool KD-3499 from your local Napa of any decent auto parts that displays KD tools.

This tool makes it so much easier to remove and reinstall the torsional spring without having it slip and snap you in the fingers.

I also show you how to make a tool to hold back the self-adjuster so they can be properly adjusted.

https://www.dieseltruckresource.com/...d.php?t=207170

Jim

 

I have a couple of brake spring tools but have found a pair of needle nose Vicegrips works better for me.

 

Ok, 3mo later I was finally able to get the drums off so I did the brake cyclinder upgrade the other day. I noticed a slight improvment. When I hit or tap the brakes is everything supposed to fly from the backseat to the front or do I still need to adjust them more. I'm thinking more adjustment is needed but wondering if anyone else just noticed a very slight improvement? thanks.

 

On my 98 there was a slight improvement (27% or so according to infidel). Not night and day difference, but definitely an improvement.

 

ok, thanks....as some of the comments reflect it to be the best thing since sliced bread. No worries, I'll take any brake improvements I can get.

 

If your brakes are not adjusted properly, you wont see much improvement. I find it best to adjust till the wheel will NOT move then back them off, with a slight drag.
also I pull the axel to make it easier to "feel" for properly adjusted shoes.

simple test after (or any time) is to apply brakes ONCE and note pedal to floor height, pump brakes and pay attention to the height difference if the brake pedal appears to rise, then without a doubt the brakes are not adjusted properly. if the height remains the same. the rears are adjusted properly