98 escort master cylinder problem?

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  #1  
Old 04-25-04, 11:58 AM
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98 escort master cylinder problem?

Hi guys:

I have replaced the master cylinder in a 98 Ford Escort (without ABS) with the 2.0 and an automatic transmission because the old one showed signs of intermittent loss of pedal height. Occasionally the old master cylinder would not come back to proper height and the pedal would feel dead for about half of the stroke, the other half of the stroke provided enough pressure to stop the car, but did not feel like it used to – i.e. lots of braking force. Other times the pedal height was fine and the car had plenty of braking power.

The problem is, the same conditions exist with the new install. I have completely bled the entire system using a “Vacula” style brake bleed kit flushing the entire system as I have done many times before with excellent results every time. I can say with confidence the system is free of air.

The rear drums have been adjusted properly and react quickly to brake pressure. The parking brake also works flawlessly.

I did however notice that when I was bench bleeding the new master cylinder (venting the 2 top ports into the filled reservoir with the bottom 2 ports plugged) that the piston inside the master cylinder would not always return to the beginning of the stroke. I thought this was because I had reinstalled the two original proportioning valves on the new master cylinder’s lower 2 ports and plugged them to prevent fluid leakage when bench bleeding.

After installing and completely bleeding the system again, the same problem as described above was happening yet again. With the car in the air and my hand on the brake pedal, I could rapidly actuate the brake pedal and force the pedal to regain full pressure at the beginning of the stroke (almost to loosen the piston back to the start of its stroke).

Do you think the piston is not returning to the start of the stroke again?

Am I correct to assume that this rebuilt master cylinder is as faulty as the original?

Has anyone else ever come across a situation as this?

Sorry for being so long winded.

Thanks.
 
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  #2  
Old 04-25-04, 02:57 PM
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Join Date: Dec 2003
Location: Indiana
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First problem I would address is the reman master cylinder. Get a new one - with a new reservoir if possible. Also, take the prop. valves apart and make sure they are clean and free of any gunk. They're just spring-loaded popoff valves, nothing to it. Next, I've always found that when bench bleeding, sealing plugs in all 4 ports is much more dependable than venting hoses. Last, I've never trusted any kind of vacuum brake bleeding tool, i.e. once bitten, twice shy. No matter how many times you've achieved the desired results with a vacuum bleeder, it will bite you eventually. Pressure (in the designed direction) is the only way to properly bleed the brake system, only extra tool required is a second body to work the brake pedal. In many cases gravity bleeding alone will do the job, although I don't recommend it with a mas. cyl. replacement.
 
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Old 04-25-04, 03:09 PM
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I vacuum bleed sometimes 10 cars in a day. Although I have had some problems with the vacula in ABS situations. I now use one of those vacuum fluid extractors with the bleeding adapter and that never has a problem, even with ABS. I think the Vacula has too strong of a vacuum pull. It can actually pull air through ABS solonoids. I do many, many brake fluid flushes that way and never have a problem. Now after addressing the Master problem, take a close look at the booster. that could be giving you some problem too.
 
  #4  
Old 04-25-04, 04:15 PM
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Join Date: Feb 2004
Location: So Cal
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Don't know what brand master you bought, but I've had lots of prodlems with the aftermarket ones in the past. Particularly in the Ford Escorts. Tried different suppliers, but always had the best results with OEM parts.

Matt
 
  #5  
Old 05-08-04, 05:05 PM
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Thanks for the advice guys. I returned the rebuilt unit and purchased a new OEM master cylinder from a local Ford dealer. Within the hour, the pedal was much higher and the braking force was just like new. Thanks Smogtek and pmheritage for that heads up.

I used my vacula bleeding system and again it worked fine (remember this car does not have ABS). I'll take heed next time I work on ABS systems as it does pull a fairly hard vacuum and I may end up pilling air through the ABS solenoids. Thanks for your insight Desi.

I also want to say that this forum is probably the best in automotive advice I've ever come across.

Keep up the good work!

Len
 
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