C1500 Brake help

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kbuskill

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Because it's not designed for the 400 and the 800's have a different brake set up.

People say they get a better pedal feel but less brake force.

Well to each their own I suppose... lol

I thought it made a great improvement. The piston inside the GMT800 master cylinder is a larger diameter than the GMT400 MC so it should produce more pressure/force.

I did use the 1 ton rear wheel cylinders which, again, have a larger piston diameter than the 1/2 ton trucks. I also upgraded to the 3/4 ton or PPV front calipers (it has been many years ago and my memory isn't the best).... again bigger than stock.

The combo worked great if I could have just been able to keep the rear brakes adjusted properly. It probably didn't help that my driveway is very steep, like 10% grade at the top, so the parking brakes were definitely getting a work out.
 
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alex s

alex s

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Soo after installing yet another MC, and bleeding it properly (not pushing too far) it seems the brakes have greatly improved. I believe they are as good as they should be now.

I really appreciate everyone's input. It has helped me a lot. And I may look into swapping a newer truck MC in the future, but for now I am tired of looking at master cylinders Lol. I have a few other things on the to-do list for this truck to get it back on the road.
 

96-2D-Hoe

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Well to each their own I suppose... lol
There's a long thread about this on GMT400 where couple people point out the differences and why you shouldn't put the GMT 800 MC on a 400. I didn't pay enough attention to be able to specify why. But couple people also said they had done the swap and felt like they had to stand on the pedal to stop and had changed back. Was enough for me to not consider it even though, like hundreds of others, I'm not currently happy with my brakes.

Hydroboost appears to be the best option to upgrade the brake system.
 

OR VietVet

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There's a long thread about this on GMT400 where couple people point out the differences and why you shouldn't put the GMT 800 MC on a 400. I didn't pay enough attention to be able to specify why. But couple people also said they had done the swap and felt like they had to stand on the pedal to stop and had changed back. Was enough for me to not consider it even though, like hundreds of others, I'm not currently happy with my brakes.

Hydroboost appears to be the best option to upgrade the brake system.

I had an 02 Tahoe LT with vacuum booster and the brakes were ok. My new to me 2005 Z71 has hydro-boost and the difference is a lot. Much better brake feel. If anyone can do the hydro-boost swap over, do it, you will be happy.
 

Enginetech

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A great trick I've used for years. Mount master, attach lines, fill master with fluid and use a modified cap and a hand vacuum pump. Suck the air out the top, fluid fills the void. Sometimes you have to move the pedal a bit (a couple half strokes). Best pedal ever and no broken masters.
 

exp500

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Jacking rear of truck when bleeding helps too- Gets that air bubble to move.
 

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