Progress Thread Finally got my first Fox Body - 1988 GT

[DudeStang]

Yeah, I think you need to go a little tighter.

I bleed my brakes a little bit differently than everyone else. I have the motive pressure bleeder, but to be honest I don't like using it.

Here's how I bleed my brakes. Get a little hose and bottle and connect to the bleeder. Crack the bleeder open enough so that fluid will come out. In the driver's seat, start pumping away. Pump to about 75-80% of full travel, lift and repeat. Leave the bleeder open the entire time and watch the flow. It should come out pretty well. Do it until no air blubbles are seen and clear fluid starts coming out. Close the bleeder, wipe it all down with a new wet rag, and move on to the next wheel


Also IMPORTANT. You need to adjust the adjustable prop valve on the firewall to full open. Screwing the valve in increased pressure to the rear brakes. Screwing it out (counter-clockwise) decreased pressure. You need to bleed the brakes with the valve fully screwed in. Mark a line on the handle and turn the valve fully in counting the number of turns until it stops. Write that down. Now bleed the brakes, and then when all done and you are confident of the pedal, unscrew the valve back to where you were previously.

Also, let us know what that number is? WHo knows if the original owner set it right. My brake setup is totally different, but mine is only set to 2 to 3 turns out from full in.


You're getting there. Keep plugging away

Going to give this a try when I get done working today. One question though...

When you connect the hose and bottle to the bleeder, do you have the hose end that is in the bottle submerged in new brake fluid? That's how I saw it done on a couple of sites/videos.

And I assume that since I'm trying to pump until I see clear brake fluid, I want to check the master cylinder level frequently to make sure it doesn't run dry.

 

[Mustang5L5]

Doesn’t need to be submerged. The fluid comes out and if you hose is 12-18” or so it is long enough to keep air from flowing bavk.

yes, keep an eye on MC fluid level. Top off every once in a while. If you run dry; you need to bench bleed again.

 

[DudeStang]

I did the bleeding process again, exactly as you described. I had the aftermarket proportioning valve screwed all the way in (slightly over 5 turns to get it all the way in). Went from rear passenger side to driver rear side to front passenger side to front driver side. Waited until I saw clear/new fluid before stopping, seemed to get most of the bubbles out (though I still saw some really tiny bubbles in the tube on the front driver side - pic below) and eventually no matter how hard or fast my wife pumped the pedal, the fluid stopped moving.


I kept an eye on the MC and added fluid every time it started to get low.

No change in the pedal feel. Still very little resistance, sort of squishy feeling. I’m close to stumped.

At this point I’m wondering if the brake booster or MC is just not engaging the way it should and maybe I need to take everything back out and start over.

 

[General karthief]

Bench bleed the master cylinder, if you can jack up the back far enough to get it level you should not have to pull it off. I would pull it just to keep the mess small but that's me.
When bleeding brakes you don't need to pump vigorously,

 

[90sickfox]

This is what you want to do. Stuff some towels under the master cylinder. Have your wife slowly press the pedal to the floor as you loosen the line closest to you. Tighten it up when her foot hits the floor. Tell her to slowly lift her foot up. Do that a couple times for each line on the master cylinder. Should be at about 3 seconds down and 3 seconds up. When she starts pushing the pedal that's when you crack the line and you want the line tightened back up before she starts letting the pedal come back up. After that have her pump the brakes 3 times and hold the pedal to the floor with both feet. Loosen the RR..and follow the order you already did. Sometimes if you pump the brakes fast the air will kinda move back and forth in the line.

I've had cars where I had to loosen the caliper bleeder as the other person slowly pressed the brake pedal... when they told me the pedal was down at the floor I'd tighten the bleeder before they slowly let the pedal up. This way you can tell which wheel has the issue by watching the stream of fluid. The rear will have less but they should be the same side to side. Hu

I bleed brakes all the time with a long tube in a partially filled ( with brake fluid ) soda bottle. This is a po man's one man brake bleeder. Install the hose in the bottle with the end submerged. Crack the bleeder loose. Really only need about 1/4 turn. Get in the car and pump the brakes about 2 seconds down and 3 seconds up. You could have her watch the bottle for bubbles. Usually only takes about 5- 6 pumps per caliper.

 

[Mustang5L5]

My guess is the bench bleed was not successful. You may need to redo it.

when you do it the next time, pivot the MC slightly side to side and forward and back to move the air around and try to purge it out. I put the nose of the MC up against a wall and push with a screwdriver.

purge as long as you need to to ensure all air is out

 

[DudeStang]

Haven’t really done anything on the Fox since my last brake bleed failure, but I did install a shock tower brace on my 2014 GT, so that’s something, lol. I also put together a video of my latest saga of failure:


View: https://www.youtube.com/watch?v=Przm3HkoaIE



I went ahead and ordered the Motive power bleeder, which arrived this week. Going to visit family for a few days so I’m planning to get back to the fox and get this brake issue fixed early next week.


These arrived this week too and fingers crossed that the Koni parts arrive soon. It would be nice to get the brakes sorted, install all new shocks and struts and drive the car some.

 

[Steel1]

I went ahead and ordered the Motive power bleeder, which arrived this week. Going to visit family for a few days so I’m planning to get back to the fox and get this brake issue fixed early next week.

Over the winter converted to 4 lug rear disc, which obviously involved new m/c, rear calipers and bleeding of the system.
Never bench bled the m/c just borrowed my buddies Motive power bleeder and away we go.
The important thing is to get the correct fitting adapter cap for your m/c , he ordered an assortment with his so I had the correct one.

 

[Mustang5L5]

Here's the write-up on the pushrod adjustment. usually you will feel a dead space before pedal resistance starts if this is incorrect, however anytime an MC is changed it should be checked. I've never really had to adjust it.

https://www.maximummotorsports.com/assets/install/pdf/brakes/MMBAK-1r1.pdf

I have a feeling the bench-bleed of the MC is the culprit. I'm guilty of this myself now and then. One trick I've found to avoid taking the MC off, is to jack the rear of the car up high enough to get the MC level. It essentially does the same thing as a bench bleed. The trick here is being able to safely get the rear end up high enough. To do it on my car, I placed two jackstands under the rear axle tube and lifted as high as it would go, and had the front a-arms sitting on small stands as low as I could set them. It did work for me.

You're getting there.

 

[DudeStang]

Here's the write-up on the pushrod adjustment. usually you will feel a dead space before pedal resistance starts if this is incorrect, however anytime an MC is changed it should be checked. I've never really had to adjust it.

https://www.maximummotorsports.com/assets/install/pdf/brakes/MMBAK-1r1.pdf

I have a feeling the bench-bleed of the MC is the culprit. I'm guilty of this myself now and then. One trick I've found to avoid taking the MC off, is to jack the rear of the car up high enough to get the MC level. It essentially does the same thing as a bench bleed. The trick here is being able to safely get the rear end up high enough. To do it on my car, I placed two jackstands under the rear axle tube and lifted as high as it would go, and had the front a-arms sitting on small stands as low as I could set them. It did work for me.

You're getting there.

Thanks. That process looks the same as what I followed from the instructions that came with the MC. I’m going to give the power bleeder a shot and see if that solves my issues. Fingers crossed.

In other news, Koni suspension finally arrived, a little over two months after I ordered them. Need to get the brakes done so I can get to work on these and the quad shocks.

 

[Mustang5L5]

You’ll be relieved to know those are much easier to install

 

[DudeStang]

Just did the brake bleeding with the power bleeder, followed the instructions exactly as they are laid out...somehow the brakes have even less resistance than they did previously. Only thing I can think of to try next is taking the master cylinder out again and checking the brake booster to make sure the pushrod is lined up correctly.

A guy in my neighborhood who is a mechanic suggested that I crack the lines at the master cylinder and have someone press brake pedal to get air out at/by the MC..and then bleed brakes in order again. Not sure I want to do that right now but when I’m not about to have an aneurism, I will give pretty much anything a try next.

 

[DudeStang]

Possible issue identified....will share when I know more, lol

 

[General karthief]

 

[DudeStang]

Just drove the Fox for the first time in two months. More details to come but this (or the lack of it I should say) appears to have been the source of my woes, lol.

 

[Mustang5L5]

I’m confused as to what I am looking at

 

[DudeStang]

I’m confused as to what I am looking at

Does this help at all? Lol

 

[Mustang5L5]

Nope. I’m still lost.

 

[DudeStang]

So I don’t know what that piece is exactly but the one in that pic is from the pedal end of the pushrod on the original brake booster. The reman brake booster had one as well but it wasn’t attached to anything...and there was nothing in the instructions about it so I didn’t do anything with it. I had not opened the original booster so I had no idea what it looked like.

At the suggestion of my mechanic neighbor, I ended up taking the pushrod out of my original brake booster and noticed that it had that plastic piece on the end of it. So it seems like the pushrod wasn’t engaging the master cylinder fully until I put that piece in (and did the measurements again).

 

[DudeStang]

Got the latest video up...has a bit more info on how I finally managed to finish it up, or at least my theories on that, lol.


View: https://youtu.be/4_KZfNUS3rs


Out of town for a few days but looking forward to driving the fox some more when I get back and then getting started on the suspension.