14ff Disk Master Cylinder and Rear Brakeline

[Adventurous 4x4]

I did rear disk on my 14ff. They work ok but I still have a little softer pedal then I like. I know there is a master cylinder from I believe a 1 ton that is a bolt on. Anybody know what I need to look for? Also on the main brake line going back to the rear brakes there is a fitting on the frame just past the rear of the t case, does anybody know what size that fitting is? It looks like that is where the line is spliced together from the factory and I think that is where I am going to tie into to go to my cutting brakes.

 

[cuervo]

I tried several of the MC listed in a lot of the conversion post here. None would fit under the hood of my 91. Some guys shimmed the brake booster to get the MC more level and clearing the hood only after taking insulation from under the hood off.

I've never had good peddle after my disc break "up grade". I'm really considering going with a hydro boost braking system because I really dislike the feel. I'm also wondering if going to a 4 wheel disc brake prop valve would help.

Also, the TSM ebrake is a joke when trying to hold my 91 Suburban.

 

[kd7kmp]

Here is the link to the thread you are talking about: http://coloradok5.com/forums/showthread.php?t=174038&highlight=perfect+master+cylinder

Kevin

 

[cuervo]

Here is the link to the thread you are talking about: http://coloradok5.com/forums/showthread.php?t=174038&highlight=perfect+master+cylinder

Kevin

Yup tried that one, would not fit under the hood.

 

[Adventurous 4x4]

I'm not worried about it fitting under the hood. As far as the upgrade goes, the disk work much better then the drums did and the pedal is about the same as it was with the drums, maybe a little better. It will actually hold the rear tires now when in 4lo on the rear axle only. With the drums the tires would just slowly turn even aired down to 8psi and on blacktop. I will cut what's left of the hood and let it stick up a little if I have to.

 

[K85 Octane]

I have that MC that is mentioned in the thread. It is holding the garage floor down with all the rest of my parts. I've taken a good look to see if it will fit and I believe it will under my '85. If it does not, there is hood crossbracing that is right above it and can easily be cut out around the MC.

 

[oldtoyboyd]

I have the 4 wheel disc master from the p30 van on my crewcab. It mounted right up to my hydraboost and it fits just fine.

 

[diesel4me]

The rear brake line should be 1/4",that is the size of that "union" fitting that joins the two sections together...I was tempted to cheat and only replace the rear line after that union on my pickup when I did the lines a few weeks back,but it looked rusty where it dissapears behind the transfer casemso I ended up buying three 60" lengths of 1'4" line and another union,that allowed me to go all the way from the proportioning valve to the rear brake hose..good thing I did because that original line had some spots that were ready to pop where you couldn't really see it !..
The proportioning valve has a 1/2"x20 thread on the rear ports,so you'll euither need an adapter that goes from 7/16"x20 to 1/2"x20,or re-use the original fitting,I cut the line off with side cutters and use a 6 point socket to get the fitting out without boogering it up if possible..

 

[Adventurous 4x4]

The rear brake line should be 1/4",that is the size of that "union" fitting that joins the two sections together...I was tempted to cheat and only replace the rear line after that union on my pickup when I did the lines a few weeks back,but it looked rusty where it dissapears behind the transfer casemso I ended up buying three 60" lengths of 1'4" line and another union,that allowed me to go all the way from the proportioning valve to the rear brake hose..good thing I did because that original line had some spots that were ready to pop where you couldn't really see it !..
The proportioning valve has a 1/2"x20 thread on the rear ports,so you'll euither need an adapter that goes from 7/16"x20 to 1/2"x20,or re-use the original fitting,I cut the line off with side cutters and use a 6 point socket to get the fitting out without boogering it up if possible..

Thanks for the info. I have to adapt it from 1/4 to 3/16 then because everything for the cutting brakes is 3/16. I might just go from the master to a adj. proportioning valve then into the cutting brakes.