3/4 ton master cylinder on 1/2 ton

[mixtapesyndicate]

So i was reading the thread about putting the 3/4 ton calipers on the the 1/2 tahoe ( http://www.tahoeyukonforum.com/forum/showthread.php?t=18093 ) and this thought came time mind as i read through some of the debate. Why not upgrade the master cylinder to the 3/4 ton master cylinder to match the 3/4 ton calipers to maybe eliminate some of the pedal travel. Just curious and also wondering your opinions or thoughts on the subject.

I like others just am not pleased with the amount of braking distance it takes to stop my hoe.

 

[SunlitComet]

Have you thought about better pads and rotors first.

 

[99Yuk]

Actually I did have that thought too. There are a couple of things that stopped me though.

1) I was scared/paranoid of getting air into the ABS pump. A master cylynder swap would most certainly introduce air downstream into the ABS pump and I don't have the knowledge or expertise to ensure proper bleeding other than lifting the rear wheels off the ground and trying to cycle the pump. Our company's auto shop is/was too busy to help me (a non-paying customer) with that.

2) I figured I'd do the other upgrades first and see if I like it and then determine if I needed to upgrade the master cyl.


In the end, I didn't need to. I havn't noticed any further pedal travel than when I was stock, and I think it feels higher and firmer post mods.


Good Luck with your plans! I'll be keeping an eye out to see how this turns out.

 

[mixtapesyndicate]

Good Luck with your plans! I'll be keeping an eye out to see how this turns out.

Your project with the caliper upgrades and pad upgrades had me thinking about it. theoretically, with a larger piston it would require a larger amount of fluid to move the piston (moving more fluid through the reservoir) so a larger master cylinder would move and store more fluid....right? Another thought was if it was a direct bolt up. As far as the ABS pump i've been kinda led to believe that you bleed bleed bleed then go out and lock up your brakes to activate (cycle fluid through) the ABS pump. Its definitely mentioned out on the internet (and on this forum http://www.tahoeyukonforum.com/forum/showthread.php?t=16799 ) that the getting air into the ABS system just sucks more than anything but it can be done.


Thoughts?

 

[SunlitComet]

Abs unit bleeding is only required if it itself is replaced or you suspect air in the unit. Changing a master cylinder should not cause any such issue other then regular bleeding. Tha abs bleed bleeds air out of the actuation hardware. So unless the computer control over brakes happened while there was air coming from the master cylinder you should not have to as the regular braking effort bypasses the computer control related accumulators,valves and pump. it just goes thru the isolation valves on the the wheels.

Just let the dealer or equivalent bleed your abs with a bi-directional scan tool. Do it your self method won't be 100%.

In short if you have crappy brake feelings and you ABS system is not activating to prevent lock up look elswhere first.

---------- Post added at 10:20 PM ---------- Previous post was at 10:17 PM ----------

And about the caliper piston and master cylinder piston. If the ratio is not kept the same effort will be effected to better or worse and the capacity of abs could play a role in that too when forced to take over braking.

 

[sparg93]

I also did the 1/2t to 3/4t caliper swap...changed to Hawk LTS pads and PowerSlot Rotors..SS lines are going on within the next few weeks.

I'm doing a full writeup on the improved braking distances from the swap. I measured my stock distances and now the pads are broken in, should be able to measure the new setup within the next two weeks.

If you REALLY want to improve brake feel, when you upgrade to the 3/4 calipers, upgrade the master cylinder with a booster. There is a writeup on the internet somewhere to do this...but it will cost some $$ and time.

 

[riso79]

Mixed tape, you are making it all a bigger deal than it needs to be. Getting air into your system is an easy fix and isn't anything to be worried about. When yoo pull off the old caliper add the new one immediately and you can manuever the lines so you virtually get no air into them. Start with the caliper upgrade, get yourself some good rotor & pads and see the difference. These trucks stop decent already for a heavy truck, this upgrade helps a ton. If that is not enough for you then worry about the master cylinder and keep going from there.

 

[96ProCompTahoe]

if you are really wanting to up the master cylindar why not just step up to the hydroboost system?

SEE LINK:
http://www.tahoeyukonforum.com/forum/showthread.php?t=1408&highlight=hydroboost

 

[sparg93]

I can confirm now, the 3/4t master cylinder will NOT bolt up to our 1/2t vaccum systems.

The piston is different...also, a 1/2t master will NOT bolt up to a hydraboost unit; you must get the right master for the right hydro or vacuum.

(sorry to bring this back from the grave)

 

[bowtiefreak]

when there is good info, always share. Old thread or not. People sometimes do use the search function and when that digs up an old thread I would hope it concludes with a solution or correct answer so regardless, thank you.