Astroboost dragging

[kaw550]

On my way home from work I noticed that it smelled like something was burning. I turned off the highway and noticed the brake pedal and steering were firmer than usual. Whe I got off the highway I noted the brakes were dragging.

I was a mile from home so I finished the ride. When I got home the front brakes were smoking.


I have a few thousand miles on the brakes (all new) Drum rear with Chevy disc up front.
I have an Astroboost with no proportions valve. Saginaw pump with a dual return.

In the spring I installed a 1/2" thick adapter plate to rotate the MC. The pushrods between the MC and the Astro master cylinder was too short so I ordered a longer one and ground it down to the stock size + 1/2".

What would cause the brakes to drag? I was concerned about the pushrod length when I installed it but it has been fine for a couple hundred miles.

Could the hydroboost have failed?

I took it for a ride a few hours later and it seemed fine.

 

[ransil]

Put some washers in to space out the push rod and try again.

 

[TOFIC]

Put some washers in to space out the push rod and try again.

ditto, you activation rod is too long or your brake pedal needs adjusting
TOFIC

 

[kaw550]

I will shorten the rod tonight. It is odd that it has been fine for a couple hundred miles and then started to drag.

 

[lilthom]

I have a similar issue but mine are just slow to release on the front discs. Rolls fine after a couple of minutes.

 

[jkskier]

I'm in the same boat. Made a little 'cap' to extend my pushrod and on longer trips lately it's been dragging and getting hot. I just took it out but have yet to do a long test drive, though.

 

[citykid]

I am going to do the same setup. Where do you get the longer push rod for the hydroboost? I also want to know whats the total length you will take off of the push rod?

 

[kaw550]

Tallon has them on their website but I could not get a response to my calls or emails.

I believe it was Vanco I ordered from They were not listed on their site. It did have to be cut and ground down.

I was surprised to find it was a used part (it was expensive)!
I ground it to stock plus the width of the spacer. I think it was 3.6".
To try and fix the issue I ground off about 1/16th. So far it is working

There was someone selling a "pill" on ebay to extend the pushrod. It sounds like what jkskier used.

 

[bbow]

Had the same issue this morning on my drive to work. The adjustable rod I have is all the way in. Added some washers to try and extend it. Fixing to go see if it worked.