need help with aerospace brakes

[robo]

hello all. i have a 91 fox lx hatch that runs mid 11's. i've recently installed a completely new brake system. it consists of a strange (mopar) manual master cylinder and aerospace 4 piston brakes at all four corners.

all the lines are new and there are no leaks. i moved the contact point for the master cylinder rod on the brake lever as indicated on the install instructions.

the system has a line lock on the front and i did not install a proportioning valve per skinny kid, who sold me the master cylinder kit.

the problem i'm having is that i cannot get the front brakes to work very well. with the line lock activated i can push the car by hitting the gas. the pedal feel is what i would consider good and firm.

i've bench bled the master cylinder and bled so much fluid through the lines that i'm on my second quart. i'm using dot 4 fluid.

the bleeders are on the top of the calipers (i think that is correct)

i'm at a loss here guys. any help or ideas would be greatly appreciated.

thanks, rob

 

[Mustang5L5]

How did you plumb the brakes to the MC and through the prop valve?

How is the braking with the line lock off?

 

[robo]

How did you plumb the brakes to the MC and through the prop valve?

How is the braking with the line lock off?

the front of the strange master cylinder is plumbed to the line lock and then from there the front lines split. the rear of the master cylinder goes to the rear brakes. (rear reservoir is larger but i've read and been advised that that is the way you want it plumbed with a drag radial and a skinny front tire) there is no proportioning valve per the strange instructions and none recommended from skinny kid either.

it is just as bad without the line lock. i just know they are not grabbing because when the line lock is activated the car will push the front when given gas. i know they are lame with regular use as they do a really poor job of slowing the car down.

any ideas?

thanks, rob.

 

[Mustang5L5]

Well, unsure of the strange mc is like other typical master cylinders, but the front port on the MC goes to the rear brakes, and the rear port is the front brakes.

Also, I believe line locks are supposed to go on the rear brake line (but not sure here) my thinking is when activated, it cuts pressure off to the rear brakes completely, and then you modulate the pedal to control the front brakes to allow for rolling through the burnout.

As for the brakes during normal 4-wheel braking, it all depends on if the master cylinder is matched correctly to the fromt and rear calipers. Is this MC specific to your exact brake kit? Did you upgrade the booster? Or is this a manual setup? Without knowing the true specs like that, hard tomspeculate why it stops poorly

 

[Mustang5L5]

Well, what vie been reading shows the line lock can install on either the front or rear brakes depending on how you want to use ot

 

[CarMichael Angelo]

Have you said what the bore diameter of the M/C is?

I was advised to put a 7/8" bore m/c on my car from Wilwood.

Just wondering.

 

[Rick 91GT]

The strange cylinder is a 1-1/8"...

You shouldnt need a prop valve, SKRC told me the same thing years ago. What size lines are you using? Braided or hard line?

So you have lines coming out of two ports on the line lock going to the front wheels?

 

[robo]

The strange cylinder is a 1-1/8"...

You shouldnt need a prop valve, SKRC told me the same thing years ago. What size lines are you using? Braided or hard line?

So you have lines coming out of two ports on the line lock going to the front wheels?

yes, two front brake lines come off the line lock and route to the front calipers. lines are 3/16". hard lines everywhere except at the front calipers and a 15" flex at the rear axle split area.

 

[merv]

att robo

hey man, did you ever fing out why your brakes are not working correctly? i just put aerospace brakes on my car and mine is doing the same thing. can't get the brakes / line lock to hold the car. my stock brakes i had no prob with? if you got them fixed or if anybody else is reading this and mite be able to help it would be greatly appreciated.i'm at my wits end with this problem. thanks

 

[junkyardwarrior]

One of the things I noticed on mine is that I had to plumb the front brakes to the front port/rear to rear port. Granted it's not a Mustang (Maverick) but still Aerospace brakes. 2 piston front and 4 piston rear (helps when staging a bracket car).

Pedal ratio on mine is 6.91:1.

My brakes are a bit like that too. They just don't work as well as I thought they should. I pulled the system apart last year (calipers) and checked them. Rears were perfect. Fronts...the calipers were sticking. Found that the bores were chewed up. Called Aerospace. Response was "it happens". I asked why and response was "misalignment". Misalignment my foot. They were installed absolutely perfect...and they are to this day. And they still don't stop as well as they should. After talking to some fellow racers about the same issue, the consensus is that Aerospace sucks, plain and simple...and they're "lack" of customer service just makes matters worse. They are cheaper than Strange or Lamb, etc...but apparently you get what you pay for. I HAD to replace both calipers--was scheduled to race in 2 weeks of that time, so I ordered two new calipers from Aerospace. That will be the last $250 I ever spend with them. The customer service totally turned me away. I love the fact that they're an American company but man, when someome makes a call looking for some insight, even if they tell me I'm screwed I'd understand...but admitting that they have seen that problem before + the short attitude did it in for me. I will have to replace the rotors soon and you betchya I'll buy from someone else.

In trying to figure out why the pedal was hard but very little braking power, I called them several times and each time the answers were the same. One word answers, seemed like they were too busy to assist me with my $1200 investment. $1200 isnt much when talking about race cars but when you have to work 140 hours to earn that, it pisses you off when you get a product that is inferior. I actually got more information out of Strange...even though my system was all Aerospace.

Also...it might be worthwhile to ask about a softer pad. I've had my pads since I put the rear calipers on in 2002 and I'm HARD on them (parking at the finish line at 150+, etc) and they still look perfect. Apparently the pad material is pretty hard. Even the stock replacement S10 pads that WERE on the car prior to Aerospace--I usually got a season out fo them and they were done. And that brake setup worked 10x better than Aerospace stuff does.