2nd Gen Non-Engine/Transmission Important Question: Do Airbags effect rear brake proportioning?

[Scooby]

I believe I read in the manual that the proportioning system "sends" more braking power to the rear brakes when a heavy load is set in the bed (or on the hitch)... Apparently the system detects the levelness of the truck.



If my airbags raise the rear of the truck to my normal height (while carrying a 3K lb. camper), does this cause the proportioning system to think there is no load back there and thus not provide additional braking power to the rear?



Thanks.

 

[LaserBob]

That's right!

 

[Scooby]

Wow, that seems silly!



Is there any way to adjust the proportioning system so that when I have a load back there with the airbags inflated I do get the added rear braking power?

 

[M Barnett]

Your truck is a lot newer than my 94, but when I installed the air bags, I put 30 lbs in them for a test drive and it definately made the brakes surge whe applied, because the rear of truck was elevated. I think it was the abs being applied. The less attitude the rear had, the less surge. I then put on Rancho 9000 shocks which brought the front end up and leveled the truck, eliminating the problem. Still haven't towed with it though.

Michael

 

[RThompson]

Great thread!

What is the device that detects the levelness?



I took out the 1" rear spring blocks to get the truck down a bit, but the rear braking has always but lacking when loaded with the weight of the fifth wheel.

 

[Scooby]

I think the device is the "brake proportioner" if I'm not mistaken. I'll need to read the service manual - unfortunately it isn't nearby at the moment - it's in my camper which is in a storage facility.



But I would like to hear if others towing/carrying heavy loads have solved this. I have seen manual brake proportioners for racing applications... .

 

[Missouri Mule]

You can disable rear proportioning valve.

Should be back by differential.

In issue 36 in Earthroamer colum he wrote about disalbling the rear proportioning valve.

 

[Steve Campbell]

Yes it does throw the rear brake...

proportioning off. You could remove the link and install some sort of adjustable cable (verneer throttle type) to allow you to "dial in" the amount of rear braking you wanted.

 

[Scooby]

Thanks for the replies, I'll check into issue 36 regarding earthroamer.



There have to be more folks who encounter this problem - don't you think??