SN95 Dead brake pedal

[04Coyoteswap]

I bought a 04 with a Coyote swap and the previous owner had a rear proportional valve and the OEM valve still installed, no abs aftermarket MC. I removed the guts in the OEM valve and used the MMS replacement plug. I bled the MC directly at the bleeder plugs and at the calipers. Now I have no pedal it goes straight to the floor, what did I do wrong? It has the hydraboost still installed, any help would be greatly appreciated, Thanks Randy Hayes

 

[RinerAuto]

Are you sure bled all the air out of the system? Not sure what you mean by bleeder plugs at MC, were ones installed there? I would rebleed only at all 4 calipers in order per service manual.

 

[04Coyoteswap]

Are you sure bled all the air out of the system? Not sure what you mean by bleeder plugs at MC, were ones installed there? I would rebleed only at all 4 calipers in order per service manual.

Thank you for the response.
In the manual for the hydro boost MC it states to bleed at the MC (actual bleeder fittings on the side) and at the caliper. I have down it 3 times with a power bleeder and 2 times with my wife helping me from inside the car. You can see where the bleeder fittings are located on the MC flat machined area with the threaded holes.

 

[04Coyoteswap]

Thank you for the response.
In the manual for the hydro boost MC it states to bleed at the MC (actual bleeder fittings on the side) and at the caliper. I have down it 3 times with a power bleeder and 2 times with my wife helping me from inside the car. You can see where the bleeder fittings are located on the MC flat machined area with the threaded holes.

View attachment 87490

The reason I started working on the brakes is the rear were not working at all. I could bleed them with the power bleeder but not with the pedal. Reading on Maximum Motorsports it states that you cannot have the OEM proportional valve and a rear remote mounted proportional valve in the same circuit. So I bought the plug and took out the guts like they say and installed a new remote proportional valve in the car. The system drained completely out and when I refilled it no brake pedal. In the Ford manual it states that hold the steering wheel to one side for up to 5 seconds and then return to center position and shut of the car to see if you have a charge. My system seems to not be charging so I need to replace the Hydro boost? It only kicks back when you start the car with the pedal pushed in a little sometimes so this is pointing at the Hydro boost? I'm sure this is clear as mud but thank you for your help.

 

[RinerAuto]

The reason I started working on the brakes is the rear were not working at all. I could bleed them with the power bleeder but not with the pedal. Reading on Maximum Motorsports it states that you cannot have the OEM proportional valve and a rear remote mounted proportional valve in the same circuit. So I bought the plug and took out the guts like they say and installed a new remote proportional valve in the car. The system drained completely out and when I refilled it no brake pedal. In the Ford manual it states that hold the steering wheel to one side for up to 5 seconds and then return to center position and shut of the car to see if you have a charge. My system seems to not be charging so I need to replace the Hydro boost? It only kicks back when you start the car with the pedal pushed in a little sometimes so this is pointing at the Hydro boost? I'm sure this is clear as mud but thank you for your help.

Ah ok, I've never dealt with a hydroboost setup before. I figured could still bleed just by gravity since you didn't have ABS. Sorry I don't have any other ideas.

 

[04Coyoteswap]

Ah ok, I've never dealt with a hydroboost setup before. I figured could still bleed just by gravity since you didn't have ABS. Sorry I don't have any other ideas.

What type of brake system do you have? Do you have the manual brake system?

 

[RinerAuto]

What type of brake system do you have? Do you have the manual brake system?

No still brake booster, but stock 1994 which is vacuum booster. But I didn't think the booster type would influence the brake bleeding process.

 

[Joe_Conehead]

Not sure if you're still dealing with this, but if the car still has its ABS system, that has its own procedure and tool for proper bleeding. Just doing it the old fashioned way won't cut it. Usually only the dealer has the Hickok NGS or Forscan tool required to adequately perform the service.

 

[blacksheep-1]

I'm trying to think, both my hydroboost cars had no problem bleeding when I went over to the Cobra calipers. I know they run off the power steering pump , but I've never had an issue with them, let me look around.

 

[blacksheep-1]

Are you using an aftermarket master cylinder? Did you change it back to stock? Did you measure the plunger depth?

 

[blacksheep-1]

Try this..

https://www.brakeandfrontend.com/operation-diagnosis-and-repair-of-hydro-boost-power-assist-systems/

 

[RinerAuto]

Not sure if you're still dealing with this, but if the car still has its ABS system, that has its own procedure and tool for proper bleeding. Just doing it the old fashioned way won't cut it. Usually only the dealer has the Hickok NGS or Forscan tool required to adequately perform the service.

You're thinking of newer cars. The SN95 ABS can be bled the old fashion way just find. The ABS pump doesn't need to actuate to get air out of it.

 

[Joe_Conehead]

You're thinking of newer cars. The SN95 ABS can be bled the old fashion way just find. The ABS pump doesn't need to actuate to get air out of it.

No. This module has been around since the nineties, at least. Newer tools, like the Forscan, also exist. It's specifically to cycle the pump to bleed the system, when air has been introduced into the pump itself. In many cases, it's the only method to yield an effective result when the problem is particularly stubborn.

If the "old fashion way" worked for the OP, he wouldn't be here asking for advice...he's already tried that and stated it earlier in the thread...