Aerospace Brake Problem ?

I have tryed everything i know and i still have hardly any brakes...I can stop the car , but its like being in a regular car and turning off the engine, and then press the brakes...Feels a little spongy, but bled them over and over and they are still not right...First problem i have had with brakes...I went with the 7.1 ratio they said use, tryed 2 other ratios & still the same....Using no p/p valve like they also told me to do...Tryed another m/c just like the one i have and also still the same...Im rinning the master cyl they make , for front disc and rear drums..All new line....

Is it a disc/drum, drum/drum or disc/disc application? A 7-1 ratio usually means manual brakes. Could you give more details for your application?

aquartlow wrote:Is it a disc/drum, drum/drum or disc/disc application? A 7-1 ratio usually means manual brakes. Could you give more details for your application?

I ordered the disc drum part # they told me....I gutted the p/p valve and made it into a T for the front brakes and added a 10 psi residual valve fro the rear drums like they ask...

After re-reading your first post my first question was already answered   . Whenever I have heard/seen the use of a gutted Proportioning or combination valve it was due to a disc/disc application. I am not a brake expert, but I have done a bit of homework when building my system. A disc/drum system usually requires the drum's circuit to be pressurized first(ever so slightly, just enough to place the shoes against the drums) to keep the rear of the vehicle from switching ends while braking, but the more the brake is depressed further the front disc brake circuit will engage at a faster rate  and with more pressure than the rear drums. This is the reason for the proportioning/combination valve that have certain split/slope values for your disc/drum brake system to operate correctly. The 10 psi residual valves keep the a bit of line pressure to the drum brakes to not allow the shoes from retracting fully, but with not too much pressure to actuate the shoes against the drums. This is a good source for brake system tech and tips http://www.piratejack.net/. I am not familiar with the Aerospace brake system, but it seems there are a few things that need addressed and/or answered. I would look into a P/P valve and/or a MC change to up the brake line pressure, which usually means a smaller bore MC or higher brake assist like a dual diaphragm booster or hydroboost application.

aquartlow wrote:After re-reading your first post my first question was already answered   . Whenever I have heard/seen the use of a gutted Proportioning or combination valve it was due to a disc/disc application. I am not a brake expert, but I have done a bit of homework when building my system. A disc/drum system usually requires the drum's circuit to be pressurized first(ever so slightly, just enough to place the shoes against the drums) to keep the rear of the vehicle from switching ends while braking, but the more the brake is depressed further the front disc brake circuit will engage at a faster rate  and with more pressure than the rear drums. This is the reason for the proportioning/combination valve that have certain split/slope values for your disc/drum brake system to operate correctly. The 10 psi residual valves keep the a bit of line pressure to the drum brakes to not allow the shoes from retracting fully, but with not too much pressure to actuate the shoes against the drums. This is a good source for brake system tech and tips http://www.piratejack.net/. I am not familiar with the Aerospace brake system, but it seems there are a few things that need addressed and/or answered. I would look into a P/P valve and/or a MC change to up the brake line pressure, which usually means a smaller bore MC or higher brake assist like a dual diaphragm booster or hydroboost application.

I have a ranger M/C with a smaller bore i been thinking about trying...Onlything i havent tryed..The P/P valve that was on my car, was the original valve on a V6...When they told me not to use a p/p valve , i just made a T out of it for the front brakes...My friend has the same setup . except he got a p/p valve for a earlier fox...The flares are different and i would have to find some adapters to run a p/p like his...

They make a "universal" type disc/drum prop valve, you can find them on Ebay or at National Parts Depot and etc. If you go to the Pirate Jacks website the will give further details on why a prop valve SHOULD be used in a disc/drum application. I hated doing all the flaring on steel lines when I re-done/modified my braking system until I bought this flaring tool from Eastwood http://www.eastwood.com/media/catalog/product/cache/1/image/412x/9df78eab33525d08d6e5fb8d27136e95/p30179.jpg , it's worth every penny in my opinion(I actually look forward to flaring lines now). Having extra adapters in the brake lines gives additional leak points, but I realize getting it "done" is a high priority.  Tee-ing the front line is fine but not having the prop valve probably is the culprit of your braking problems, IMO. Good luck and keep us posted. Todd

aquartlow wrote:They make a "universal" type disc/drum prop valve, you can find them on Ebay or at National Parts Depot and etc. If you go to the Pirate Jacks website the will give further details on why a prop valve SHOULD be used in a disc/drum application. I hated doing all the flaring on steel lines when I re-done/modified my braking system until I bought this flaring tool from Eastwood http://www.eastwood.com/media/catalog/product/cache/1/image/412x/9df78eab33525d08d6e5fb8d27136e95/p30179.jpg , it's worth every penny in my opinion(I actually look forward to flaring lines now). Having extra adapters in the brake lines gives additional leak points, but I realize getting it "done" is a high priority.  Tee-ing the front line is fine but not having the prop valve probably is the culprit of your braking problems, IMO. Good luck and keep us posted. Todd

All the flare tools i bought and the loaners from part stores, were junk...Thats why i raided every parts store where i live & they let me find what i needed to adapt everything...You fave a part # on that flare tool...thanks

colormebad wrote:

aquartlow wrote:They make a "universal" type disc/drum prop valve, you can find them on Ebay or at National Parts Depot and etc. If you go to the Pirate Jacks website the will give further details on why a prop valve SHOULD be used in a disc/drum application. I hated doing all the flaring on steel lines when I re-done/modified my braking system until I bought this flaring tool from Eastwood http://www.eastwood.com/media/catalog/product/cache/1/image/412x/9df78eab33525d08d6e5fb8d27136e95/p30179.jpg , it's worth every penny in my opinion(I actually look forward to flaring lines now). Having extra adapters in the brake lines gives additional leak points, but I realize getting it "done" is a high priority.  Tee-ing the front line is fine but not having the prop valve probably is the culprit of your braking problems, IMO. Good luck and keep us posted. Todd

All the flare tools i bought and the loaners from part stores, were junk...Thats why i raided every parts store where i live & they let me find what i needed to adapt everything...You fave a part # on that flare tool...thanks

Eastwood #25304, a bit pricey but will put a big smile on your face just after doing one flare!

aquartlow wrote:

colormebad wrote:

aquartlow wrote:They make a "universal" type disc/drum prop valve, you can find them on Ebay or at National Parts Depot and etc. If you go to the Pirate Jacks website the will give further details on why a prop valve SHOULD be used in a disc/drum application. I hated doing all the flaring on steel lines when I re-done/modified my braking system until I bought this flaring tool from Eastwood http://www.eastwood.com/media/catalog/product/cache/1/image/412x/9df78eab33525d08d6e5fb8d27136e95/p30179.jpg , it's worth every penny in my opinion(I actually look forward to flaring lines now). Having extra adapters in the brake lines gives additional leak points, but I realize getting it "done" is a high priority.  Tee-ing the front line is fine but not having the prop valve probably is the culprit of your braking problems, IMO. Good luck and keep us posted. Todd

All the flare tools i bought and the loaners from part stores, were junk...Thats why i raided every parts store where i live & they let me find what i needed to adapt everything...You fave a part # on that flare tool...thanks

Eastwood #25304, a bit pricey but will put a big smile on your face just after doing one flare!

I noticed this diagram on the site you posted , shows the front port of the m/c is front and rear port is rear brakes....All other m/c like strange & aerospace says the front is the rear and the rear port is the front..

It's possible you might have the master cylinder plumbed backwards from OEM. Or the m/c bore might be too large for the pedal ratio used and/or the system's volume needs. Or the pedal ratio used might be too small for the m/c bore size and/or the system's volume needs. You also need to make sure the pedal/pedal ratio used allows the pushrod to line up correctly with the m/c so the pushrod doesn't end up in a bind during full pedal travel. Also need to look at how much OEM rubber/steel braid brake line is used on the car. This is because you can end up with a spongy pedal if you use more flexible brake line (vs hard line) than the car really needs.


On most any disk/drum master cylinder (regardless of m/c car brand) that has both a small volume reservoir and a larger volume reservoir, the larger reservoir port is meant for the front disk brakes because disk calipers have larger volume needs than the rear drums. On m/c's that have 2 reservoirs the exact same size it can sometimes be a guessing game what port goes where depending on the m/c car brand & year.  


From what I have heard some (maybe most, but I don't know for sure) chebby m/c's plumb rear port (closest to mounting flange/firewall) is rear brakes, and front port is front brakes.


The popular Mopar m/c (and the aftermarket Mopar copies like from Strange, A.R.T., etc) plumb rear port (closest to mounting flange/firewall) goes to front brakes, & front port goes to rear brakes.


IIRC every Ford m/c (cast Iron & aluminum) I have used plumbs the same as the Mopar (rear port goes to the front brakes, front port goes to the rear brakes).


If you plumb the average "drag car" (with narrow front runners) like any standard OEM brake setup is plumbed (where the front brakes always apply first, then the rears join in), some cars will sometimes lockup & slide the skinny front tires if you get on the brakes hard enough. Because of this some people plumb drag cars with the m/c ports "backwards" from OEM to send less pressure/volume to the skinny fronts, and more pressure/volume the the big rear tires. The "best" way to plumb a drag car m/c (OEM vs backwards) depends on who you talk to & type of race car/intended purpose. The big drawback to plumbing the brake system backward on a drag car (to avoid locking up the fronts) is if you happen to lockup the rear tires at speed it can be much more dangerous than the fronts. Locking up the rear brakes and having the car swap ends at speed is the last thing you want to do in a drag car.

DILLIGASDAVE wrote:It's possible you might have the master cylinder plumbed backwards from OEM. Or the m/c bore might be too large for the pedal ratio used and/or the system's volume needs. Or the pedal ratio used might be too small for the m/c bore size and/or the system's volume needs. You also need to make sure the pedal/pedal ratio used allows the pushrod to line up correctly with the m/c so the pushrod doesn't end up in a bind during full pedal travel. Also need to look at how much OEM rubber/steel braid brake line is used on the car. This is because you can end up with a spongy pedal if you use more flexible brake line (vs hard line) than the car really needs.


On most any disk/drum master cylinder (regardless of m/c car brand) that has both a small volume reservoir and a larger volume reservoir, the larger reservoir port is meant for the front disk brakes because disk calipers have larger volume needs than the rear drums. On m/c's that have 2 reservoirs the exact same size it can sometimes be a guessing game what port goes where depending on the m/c car brand & year.  


From what I have heard some (maybe most, but I don't know for sure) chebby m/c's plumb rear port (closest to mounting flange/firewall) is rear brakes, and front port is front brakes.


The popular Mopar m/c (and the aftermarket Mopar copies like from Strange, A.R.T., etc) plumb rear port (closest to mounting flange/firewall) goes to front brakes, & front port goes to rear brakes.


IIRC every Ford m/c (cast Iron & aluminum) I have used plumbs the same as the Mopar (rear port goes to the front brakes, front port goes to the rear brakes).


If you plumb the average "drag car" (with narrow front runners) like any standard OEM brake setup is plumbed (where the front brakes always apply first, then the rears join in), some cars will sometimes lockup & slide the skinny front tires if you get on the brakes hard enough. Because of this some people plumb drag cars with the m/c ports "backwards" from OEM to send less pressure/volume to the skinny fronts, and more pressure/volume the the big rear tires. The "best" way to plumb a drag car m/c (OEM vs backwards) depends on who you talk to & type of race car/intended purpose. The big drawback to plumbing the brake system backward on a drag car (to avoid locking up the fronts) is if you happen to lockup the rear tires at speed it can be much more dangerous than the fronts. Locking up the rear brakes and having the car swap ends at speed is the last thing you want to do in a drag car.

Aerospace called me about 4 hours after they closed and we went over everything under the sun...I had already tried everything he mentiioned...He said they would take the m/c or any part of the brakes back and check them...I told him about a friends car i put the same mopar m/c on, he has stock front disc brakes and stock drum brakes, and has 5 times the brakes i have, and im the one who installed his and many more...Never had this issue before...Years ago i ran a m/c off a 76 ford F100 and it worked flawless..This mopar type m/c is using the rear for front and front port for rear....I see alot of guys running v6 ford ranger m'c's also....I ask him if he thought this 1.125 bore was too big and he said no, do not change it....After this long talk, he said your brakes may not be much better...That i know is not true...I will bleed some more and look for other problems...I have already tried 2 brake pedals with 3 different ratios with no affect...Have it on a 7:1 ratio right now...Both bleeders were facing down when i noticed it after i already was bleeding the brakes' They told me back then, their is no left or right, just put the braided line where the bleeder is and put the bleeders on the top...Thats what i did but no affect also...

A 7:1 pedal ratio should give plenty of pressure(this is more of a manual brake pedal ratio as compared to a power brake pedal ratio, like a 4 or 5:1), with the right MC bore of course.  A 1.125" master will give more fluid volume but at a reduced pressure as compared to a 1" bore MC using the same pedal effort. Just a 1/16th of an inch change in MC bore diameter can make quite a difference in braking power. IMO, I would try a 1" bore MC first, your pedal "feel" and/or effectiveness  should increase greatly. You may still have to employ a prop valve though, to get the two systems(disc/drum) to work together correctly. Make sure the MC is for a disc/drum application and you get all the air out of the system! Good luck and keep us posted.

aquartlow wrote:A 7:1 pedal ratio should give plenty of pressure(this is more of a manual brake pedal ratio as compared to a power brake pedal ratio, like a 4 or 5:1), with the right MC bore of course.  A 1.125" master will give more fluid volume but at a reduced pressure as compared to a 1" bore MC using the same pedal effort. Just a 1/16th of an inch change in MC bore diameter can make quite a difference in braking power. IMO, I would try a 1" bore MC first, your pedal "feel" and/or effectiveness  should increase greatly. You may still have to employ a prop valve though, to get the two systems(disc/drum) to work together correctly. Make sure the MC is for a disc/drum application and you get all the air out of the system! Good luck and keep us posted.

Yeah' the m/c says it works with oem disc front and drum rear...and 4 wheel disc also....
I have a v6 ranger m/c i been thinking about trying...Lots of guys use them i know...

I did notice earlier that on this 4 piston cal' that when i pump the brakes....The inside pad hits the rotor' then retracts... and u can move the pad with ur hand...The outside pad is real snug and the rotor drags on that outside pad on both sides....they use one bleeder for a 4 piston caliper- strange uses 4 bleeders for a 4 piston...Wonder if air is still on that one side ??

If you think there is air still trapped in one or more calipers you may be able to remove the trapped air(bubbles) by tapping on the caliper with a wrench or light hammer while you have the bleeder screw open (like being gravity bled) so you can see if any air is removed. Remember light taps and keep the MC reservoir full!

aquartlow wrote:If you think there is air still trapped in one or more calipers you may be able to remove the trapped air(bubbles) by tapping on the caliper with a wrench or light hammer while you have the bleeder screw open (like being gravity bled) so you can see if any air is removed. Remember light taps and keep the MC reservoir full!

Thats what a few more mentioned also....I tryed that about 1 hour ago...The fluid coming through the clear line i have , had no bubbles at all....Im just about ready to try a smaller bore m/c

I just noticed that you said that your bleeders were pointing down???? If so they need to be on top so that the air will bleed out. There was a thread on this same problem awhile ago and flipping the calipers solved the problem. (could have been on the other site too) Hope this helps.

jeffgfg wrote:I just noticed that you said that your bleeders were pointing down???? If so they need to be on top so that the air will bleed out. There was a thread on this same problem awhile ago and flipping the calipers solved the problem. (could have been on the other site too) Hope this helps.

I noticed they were pointing down and insted of changing them , i call aerospace and they said just put the braided line where the bleeder is and the bleeder where the line is...I have them both on top now and rebled and no differance..He told me to check my pressure and i shout have between 1000-1100 on the front disc and the rear drums..I had that on the front when i checked once before on the 3nd pump...Im fixing to check the rears today....The rear has a different size bleeder, so i have to find a adapter to fit my gauge....