1988 LSC Mark VII Brake Problem

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redcatman74

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Problem:

Had intermittent problem with losing brakes (both check brake and brake warning lights on at the same time). The problem would go away and then come back.

Took it to a Goodyear dealer to get new pads, and new fluid.

Problem with intermittent lose of brakes continued and then was permanent.
Currently I have no power assist brakes - very hard and ineffective brakes - Car is unsafe to drive like it is.

both check brake and brake warning lights on

pump does not turn on

So far I have:

read posts on abs and tried to follow recs as best I could.

Checked relays and fuses - seem to be ok

put code reader on, at the check brake light I got two flashes, long pause, one flash, pause, and then constant on - not sure if that is a 21 (main valve) or 22 (left front inlet valve)

At this point I don't know how to proceed. I don't have a repair manual (trying to find one even though I don't know if it would help).

Anyone have suggestions on where to go from here. I hate to think I may have to junk the car.

Also, is the brake system on the 1988 Lincoln Town car the same as the 1988 Mark.

Thanks

RCM74
 
I appreciate the reply. However, I need some advice on how to diagnose the problem rather than replace one item, see if it fixes it, then another, and so forth. There should be a "routine", so to speak, on where to start given the symptoms. If I haven't given enough information, let me know and I will try to get it.

RCM74

Sifrino3 said:
Brake Booster, I seemed to have that same problem. . .
Click to expand...
 
I didn't replace mine. I took it in. Because I was having one brake problem after another. It was't like replacing and then replacing. Still not finding the problems. Its just the MVII brakes suck. One of the worst things on this car. I still can't believe I havnt upgraded them. . .
 
I took it it in to the Lincoln dealership where I bought the car. When they could not give me a difinitive answer on what was wrong (they "suggested" the pressure switch at a cost of $600), I said no way. I asked for the "error" codes and they could not produce them.

Given the car is worth less than $1,000 at wholesale, I need to find the problem and fix it myself.

I am looking for someone on this forum that can recommend some diagnostic steps to find the problem before I spend any time and money looking for parts.

Also, anyone on the list know if the brake system on the 1988 Town Car are the same as the 1988 Mark VII?

RCM74
 
The Mark VII ABS system is unique to the Mark VII; no other car has the same system. The first thing I would do is bleed the brakes personally. You cannot bleed these brakes like a non-ABS car, there is a bit of a procedure to it. I would not trust Goodyear to know this and would be concerned that they did an improper bleeding process. This page is quite helpful: http://www.lincolnsonline.com/article21.html. I would follow the steps there. Towards the bottom the bleeding process is described. Also, I would test the accumulator. This is easily done. With the car on, pump the brakes. If you hear the accumulator kick on before pump 3 or 4, it is most likely weak and needing replacement. Good luck.
 
I had planned to eventually bleed the brakes again but did not think that would be the reason that the pump doesn't come on.

Would a problem with how the brakes were bled cause an error condition that would not enable the pump to come on?

Remember, the brakes worked sporadically before I took it into Goodyear to have the brakes worked on and it worked the same way after I got it back until it failed permanently.

RCM74

JoshMcMadMac said:
The Mark VII ABS system is unique to the Mark VII; no other car has the same system. The first thing I would do is bleed the brakes personally. You cannot bleed these brakes like a non-ABS car, there is a bit of a procedure to it. I would not trust Goodyear to know this and would be concerned that they did an improper bleeding process. This page is quite helpful: http://www.lincolnsonline.com/article21.html. I would follow the steps there. Towards the bottom the bleeding process is described. Also, I would test the accumulator. This is easily done. With the car on, pump the brakes. If you hear the accumulator kick on before pump 3 or 4, it is most likely weak and needing replacement. Good luck.
Click to expand...
 
Making some progress.

I found I had power at the pump relay. To check to see if the pump worked, I removed the top of the relay and manually switched it on, which I've got to believe mimics the pressure switch activating.

The pump worked and charged the accummulator enough that when I moved the car the brakes worked. The relay will not reenergize on its own and the two brake warning lights do not go out

Now the next question is - does this point directly at the pressure switch as the problem or are there other parts that could cause the pressure switch not to work correctly and the brake warning lights to go out?

RCM74
 
Your ride is 16 years old at this point so don't get discouraged.

The brake section of our shop manual (Group 12) is the LARGEST independant section of the manual. I have a boatload of respect for the guys that work on my brakes. Even with the manual in hand, I'll only perform routine maintenance.

The 1988 brake assemblies are more available (and less expensive) than the 1990 and up.

If a full bleed and new pads don't correct it, I take it to The Man.
 
Hey RCM74

If it does turn out to be the pressure switch than I can order one for you. The part number is E7SZ-2C244-A list price is 198.24 and LVC cost would be $115.97. I used to sell a lot of them for that concern you are describing but I am not one to throw parts at a concern til it is fixed!! As for the procedure to diag the problem, you are in the right place to gather the info...unfortunatly our manual does not cover that year so I cannot help there.
Max
 
After following the advice from a person that knows the pin out connections from the pressure switch connection to the relay that operates the pump, I have positively determined that the problem is the pressure switch. His advice was:

"Next shunt the presure switch connector contacts. This connector has 5 pins. Pin 1 and 4 are the relay control. The pin count is as follows; looking at the connector with the three connctors on top, count left to right from the top and left to right on the bottom, 1,2,3, then 4 and 5. The other connectors are the signal feeds to the control module to light the warning lamps etc. If the relay pulled up, you know the pressure switch is faulty."

I am was planning on buying the pressure switch from Ford until I heard the offer from mrzeee. In the meantime I called my primary salvage yard source. After being referred from one yard to another, on the fourth try I found a complete assembly for $125. They had two and had just sold one to a repair shop. I plan to pick the other one tomorrow.

I haven't taken the pressure switch off yet but did buy the plumbers socket kit that has the right size socket to remove and replace it. One can only hope it will come out without any problems.

One thing is clear, which many of you may know, the '80's Lincolns are getting harder and harder to find. In the last 3 months, these 4 salvage yards alone have crushed their last eleven (11) 1988 Lincoln Mark VIIs that they had on their lots. They doubted the will get any more in stock. The reason was due to a simple financial formula as stated by my primary salvage yard. They said they won't even consider another one given the low payout for parts on the cars. They say to get a car in house runs about $300-400 and needs to have a minimum parts value of $1,500, which they don't see for that vintage car.

I have a friend that had a mint condition 1988 Lincoln Town car 2 weeks ago. She wrecked it with moderate damage to the front end (engine bay components intact) and it was totaled by the insurance company. Given she didn't know I might be interested in the car, she signed the title over to the towing company. They will put it up for auction. However my primary salvage yard which is one mile away from the towing company lot said they weren't interested in it even if the car cost them nothing.

As has been discussed before on one of the Lincoln forums, if you find some critical parts, better buy them. They will continue to become more scarce and expensive.

RCM74
 
redcatman74 said:
...
As has been discussed before on one of the Lincoln forums, if you find some critical parts, better buy them. They will continue to become more scarce and expensive.

RCM74
Click to expand...
I had to quote you Bro because it's true.

I've tried to convince guys here in Philly that if THREE PEOPLE each put up ONE HUNDRED DOLLARS then they can collectively BUY A PARTS CAR and store it at the location of their choosing until stripped.

If person one takes the brake assembly, they've made their money back.
If person two takes the altenator and regulator, they've made their money back.
If person three takes the air compressor and dryer, they've made their money back.

I have a parts car in storage and one for sale. Guys; don't let these rides go to the yards. Vultures will destroy the entire dashboard to get to a $25.00 heater core.
 
I bought an ABS assembly from a junkyard that just got in an '88 Mark. I bought the plumbers socket set that had the 1-7/16 socket that was recommended to remove the pressure switch. However, the 1-7/16 socket that was specified is too big, the next size down, 1-11/32 is too small.

My questions now are, 1. what is the size of the socket, and 2. where can you find a thin wall, deep socket that can be used to remove the pressure switch?

RCM74
 
Last edited:
redcatman74 said:
I bought an ABS assembly from a junkyard that just got in an '88 Mark. I bought the plumbers socket set that had the 1-7/16 socket that was recommended to remove the pressure switch. However, the 1-7/16 socket that was specified is too big, the next size down, 1-11/32 is too small.

My questions now are, 1. what is the size of the socket, and 2. where can you find a thin wall, deep socket that can be used to remove the pressure switch?

RCM74
Click to expand...
Sounds metric to me ....
 
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