27mm Break Cylinders vs Rear Height Sensing Unit?

[Ben Rumson]

I'm wearing out my front pads 6 to 1 over my rear drum linnings.



Found TSB 05-04-97 that says to replace the rear wheel break cylinders with larger 27mm ones only if you haul continuously at or near 75% of GVW. TSB 05-04-98 discusses removing the rear height sensing unit under similar load circumstances.



I DO NOT haul this heavy continuously, but am wondering what it would hurt if I went ahead and switched to the larger 27mm cylinders anyway OR possibly removed the rear height sensing devise.



Looking for any advise or feedback from someone who's already done this or has experience in this area.



Also, if it's OK to modify the rear break setup, would you recommend removing the height sensing unit before replacing the cylinders?



Thanks

 

[illflem]

After I learned to manually keep the rears adjusted every 5k and switched to Carbomet pads it's been over 75k on the same pads. Beforehand it was new pads every 15k. I strongly suggest you try the same. Carbomet pads are available from TDR brake guru Sam Peterson at -- email address removed --

 

[Bigramguy]

Do the wheel cylinders first,and see how it feels. You should notice a fair increase in braking power. That way you still have the height sensing proportioning valve which increases brake pressure in response to the load in the bed.



If you find it's still not enough,then bypass the valve.



I have done both on mine,and it stops great,front pads last much longer. Only problem I have is the rears are a little touchy on ice or wet pavement if you get on the brakes hard. Once you get used to it and don't hammer on the brakes too fast in those conditions it is fine.

 

[Cooker]

I don't think TSB 05-04-98 applies to your truck, as it is a 1995. As far as I know, your truck doesn't have a rear hight sensing valve.



The rear wheels cylinders do make a difference but as illflem said, it is also very important to keep your brakes properly adjusted as well.

 

[Ben Rumson]

Properly Adjusted?

I've always been under the impression/understanding that working the pedal several times while backiing automatically adjusted the rear breaks...



Is this something not happening AND should I manually adjust the star wheels by hand every so often???

 

[Bigramguy]

Sometimes backing up is not enough to adjust them. It only takes a sec to crawl under and do them manually. Next time you have the drums off,make sure the adjusters are cleaned up and lubricated with anti-sieze.



I do them everytime I have the truck in the shop,or if the pedal feels low. Makes a big difference.