I am having a problem with the brake system on a 2004 Escape

First, I diagnosed the vehicle for a lost of brake pressure and found the RR brake hose rip and loosing brake fluid. I replace the RR brake hose and retrieve the service information for bleeding the brake system (wheels RR,RL,FR,FL) one thing that the service information advise was to bleed the ABS pump with a scan tool, I did not have a scan tool with bi-directional control. After bleeding the brake system the brake system did not hold pressure, brake pedal was not stiff. I check for brake fluid leaks and did not find any.

One thing I notice, on the RR wheel when I open the bleeder screw (I'm pressure bleeding the brake system) the pressure volume is lower than the pressure volume than the RL wheel. I see more brake fluid coming out of the RL wheel than the RR wheel, front brake calipers ok. So I replace the RR wheel cylinder and the brake hoes three times already, I still have the same problem.

I was advise to clamp down the RR hose and check and see if the brake pressure improves.

So the brake pressure does improve when I clamp down the RR brake hose. I had replaced all the brake lines and master cylinder so I when on and replaced the abs pump with a use pump from a parts retailer.

I already replaced the wheel cylinder and brake hose three times on RR wheel, when I step on the brakes the rear brakes do apply but I'm having trouble with brake pressure.


So next a buddy of mine loan me his modis scan tool and I bleed the brake system, instructed by the service information. Bleed the brake lines first them bleed the abs pump and then bleed the brake lines again..

What has me confuse the brake pedal stays stiff with the engine off but after I turn the vehicle on the depress the brake pedal and it feels normal for about 2 seconds then it losses brake pressure. I bleed the brake system over and the brake system still does not hold pressure.

I replace all the brake lines, replace the master cylinder and still have the same problem with the brake system.

After all the brake system components I’ve replaced I still not able to get the brake system to hold brake pressure.

I need help!

 

Without getting into a lot of questions,
Where did you get the master cyl, and was it new ?
Did you bench bleed the master before installing ?

I have had more than one instance where the master was defective right out of the box.
The valves in the ABS unit have to be held open when bleeding so all the trapped air can get out.
There may be more than one problem.

 

Thank you for replying!

I did bench bleed the new master cylinder. I purchase the part from rockauto.
I used modis scan tool to bleed the ABS pump. I followed the service information for bleeding the brake system.
There is trap air or like I mention in my first post the problem started with the RR brake hose I there is something happening there.

Thank you.

 

Let's take a different approach on this, OK ?
If,,,,,,, the RR brake hose was damaged, what about the brake line tubing itself that goes to the RR wheel cyl?
Something had to get in there to damage the hose and it probably damaged the line too. Were you able to check that entire line back from the wheel cyl to a more protective part of where the tubing runs?
With no visible leaks and loss of pressure , I would be very suspicious of the master cyl. leaking internally.
If you can't find anything wrong there you may need to replace the ABS control unit under the hood.
Before going any further , let's see what you find upon closer examination.

 

After replacing the RR brake hose (second brake hose) I replaced the brake line tubing from the wheel cylinder to the brake hose.
After bleeding the system and not being able to get pressure in the system I replaced all four brake lines. I replaced the brake lines from the master cylinder to the abs pump and from the abs pump to the wheels of the vehicle. After that and still no brake pressure I replaced the ABS pump, still have the same problem.
I'm going to replaced the master cylinder one more time.
The master cylinder that is on the vehicle now, I removed it, bench bleed the cylinder and block off the two ports and push in the piston and it was able to hold pressure. Installed back on the vehicle bleed the system and still have the same results.

I just have my head-wrap-around the low brake pressure volume on the RR side when I open the bleeder, and the RL side is shooting out good pressure when I open the bleeder.
Also, I did mention that I clap off the RR side brake hose and the system is able to hold pressure. Other technicians keep telling me to change the brake hose and wheel cylinder. I replaced those parts and still no fix.