Teves ABS Pump never stops

[Aztec62]

Hi all,

today I tried to other pump (the one wich came with the Reatta). Same picture.

I then removed the pump and discovered the reservoir filter was blocked again.

Then I connected the pump motor to 12 VDC, fluid was coming from a makeshift reservoir with no filter.

I had the whole assembly on my workbench and tried to purge the air out of the pump.

After a lot of fiddling and I don´t know what not the pump finally began to build up pressure.

I quickly installed it in the car and got all the air out.

This was really messy because you have to waste a lot of brake fluid to get all air out.

The units sprays fluid in all directions.

Then the pum began to charge the accumulator and lo and behold, the pump actually stopped with the pressure in the limits (i think).

Pressed the brake pedal three times and the pump began to work again.

Only this time it did not stop.

Further investigation revealed the pump again refuses to build pressure.

The reservoir was full of fluid and all looked OK.

(Insert curse words of your choice here)

This stuff is a real PIA.

Since this is a German design and me being German, I think I owe you guys an apolgy.

Small wonder, Teves came up with something a lot better the next year.

91 Buicks already had the Mk. 4 Teves anti lock brakes system with a conventional brake booster, wich is almost trouble-free.

 

I will try a German Ford Scorpio Forum next, maybe they can help.

I am at my whits end.

 

Have fun,

Henning

[Ronnie]

Sorry to hear you are still having problems. It seems to me like a pump that you know is good must be getting air into it from somewhere or starving for fluid for it to stop building pressure. I've never heard of anyone having this problem before with a good pump. Let us know what solves the problem. It might help other Reatta owner in the future.

[Aztec62]

Ronnie,

I have found a drawing wich explains how the pump works.

It is from a German language Volkswagen training book for car mechanics.

Volkswagen had this system optional in the Mk.2 Golf.

 

[Ronnie]

Thanks for the information and the translation. From the diagram can you tell what might be preventing your pump from building pressure? When you changed pumps did you swap out the entire pump/motor/accumulator and pressure switch? or just the pump it's self?

[Aztec62]

Ronnie,

I haven´t had a look at the non-return valve yet, but my hopes are pretty low.

 

I have just swapped the pump itself, The Ford unit connectors for pressure switch and pump motor are different.

I tried both accumulators, But this is not an accuimulator issue anyway.

 

A pump able to put out such high pressures must meet pretty tight manufacturing tolerances.

Maybe both pumps are simply worn-out.

They do not suck in fluid and there is no pressure build-up.

The electric motor runs fine.

[Ronnie]

I'm out of suggestions on this one. I do find it odd that the filter keeps clogging up on the reservoir. What would cause that? Is it possible that DOT 5 brake fluid with silicon has been added to the system? Dot 5 is silicon basedand cannot be used. The ABS valves & solenoids will aerate silicon (perhaps the pump too) and the pump may not get proper lubrication with silicon based fluid.

[Aztec62]

Well, my makeshift reservoir did not had a filter. But that did not help.

I am using DOT 3 brake fluid but god knows what stuff had been used by the previous owners.

The complete brake system has been rebuild and refilled with DOT3.

There is nothing else in the system anymore.

 

 

It is not possible to open the pump to have a look inside.

I find it ood that it takes so much trouble to get the air out of the pump.

Nobody else ever had similar problems?

[Ronnie]

 

After a lot of fiddling and I don´t know what not the pump finally began to build up pressure.

I quickly installed it in the car and got all the air out.

This was really messy because you have to waste a lot of brake fluid to get all air out.

The units sprays fluid in all directions.

Then the pum began to charge the accumulator and lo and behold, the pump actually stopped with the pressure in the limits (i think).

Pressed the brake pedal three times and the pump began to work again.

Only this time it did not stop.

OK. Up to the point of pressing the brake pedal you were filling the accumulator which had little or no air in it. Then the pump shut off as it should. So, what would have happened when you pressed the brake pedal is the fluid whet into the brake lines and the pump helped push it in. What I'm thinking might have happened is any air in the lines (and there might have been a lot compressed by the pump) was forced back into the pump somehow. Do you think there could be air still trapped in the brake lines or the ABS valves?

 

If this was a normal brake system you could tell if there is air trapped in the system by having an assistant slightly, and slowly, press the brake pedal just a small amount while you observe the fluid in the reservoir. Watch  for any signs of tiny bubbles coming up through the fluid. If you see any bubbles you still have air in the system. I don't know if that test will work on the TEVES system or not but it wouldn't hurt to try.

[Aztec62]

OK. Up to the point of pressing the brake pedal you were filling the accumulator which had little or no air in it. Then the pump shut off as it should. So, what would have happened when you pressed the brake pedal is the fluid whet into the brake lines and the pump helped push it in. What I'm thinking might have happened is any air in the lines (and there might have been a lot compressed by the pump) was forced back into the pump somehow. Do you think there could be air still trapped in the brake lines or the ABS valves?

 

If this was a normal brake system you could tell if there is air trapped in the system by having an assistant slightly, and slowly, press the brake pedal just a small amount while you observe the fluid in the reservoir. Watch  for any signs of tiny bubbles coming up through the fluid. If you see any bubbles you still have air in the system. I don't know if that test will work on the TEVES system or not but it wouldn't hurt to try.

 

Ronnie thank you for all the help.

Be there air in the pump from whatever source.

Why has it been possible to purge the pump from all the air inside and suddenly after pressing the brake pedal a few times it is not possible anymore?

After pressing the brake pedal i tried to purge the pump just like i did before hitting the brakes.

But there was no fluid coming anymore with a full reservoir an no restriction from a filter or wahtever.

 

I just found another Teves unit from a Ford Scorpio on Ebay Germany. Maybe this  one yields a good pump.

[Ronnie]

I  hope that works for you. You certainly have more tenacity than I do. As much trouble as you've had out of that Reatta I would probably have given up and moved on to something else.

[2seater]

I do admire your tenacity too. I know when doing the brake accumulator tests that even with a 500ml column of fluid extending far above the pump, I would still find a stubborn bubble lodged against the inlet nipple to the pump. Priming the pump did require opening the pressure relief valve quite a ways and circulating at least 100ml to get clear fluid. My test setup uses a clear inlet hose so the trapped air was visible but generally once bled, it didn't come back. If the pump built pressure once, it would seem it should be able to do it again.

[Aztec62]

I do admire your tenacity too. I know when doing the brake accumulator tests that even with a 500ml column of fluid extending far above the pump, I would still find a stubborn bubble lodged against the inlet nipple to the pump. Priming the pump did require opening the pressure relief valve quite a ways and circulating at least 100ml to get clear fluid. My test setup uses a clear inlet hose so the trapped air was visible but generally once bled, it didn't come back. If the pump built pressure once, it would seem it should be able to do it again.

 

2seater,

you are referring to the non-return (or check-) valve, am I correct?

The pressure relief valve is located inside the pump, behind the pressure switch.

 

I would think the same. Once bled, the pump should work.

That is what makes me so mad.

Nobody else seems to have such problems. The German car forums show very little information about the Teves Mk.2.

Either nobody dares to touch it or it was not as much in use as on US cars of that age.

Back in 1990 few new car buyes ordered it in Germany when it was optional, because it was very expensive.

The only car wich had it as standard over here was the Mk.1 Ford Scorpio (Merkur Scorpio in the US) and these cars are all scrapped.

Nobody keeps them as a future classic car.

[DAVES89]

The Saab from the late 1980's to early 1990's have the Teves system. It is so similar that the front sensor leads with a little alteration will work on our cars. You may want to check their forum. Also Jaguar.

[Aztec62]

Hello all,

I think I have found something really exciting.

There is a company in Germany wich claims to be able to repair the accumulator ball!

Check it out (german language):

http://www.texerv.com/abs-druckspeicher.html

They say they can recharge the ball with nitrogen as long as the diaphragm is in good shape.

To check it says on their website to insert a suitable tool (no pointy tip) into the ball and push hard.

When there is strong resistance after a little less than an inch (2cm), the accumulator still holds a charge and is probably repairable. When it is possible to insert the tool almost all the way, there is no charge and the diaphragm is probably gone.

It is not a 100% certain test, as even with no nitrogen charge when tested, the accumulator might still hold a new charge.

 

The website is almost all German language, but I am pretty certain they are able to speak English, too.

 

Have fun

Henning

[Ronnie]

They say they can recharge the ball with nitrogen as long as the diaphragm is in good shape.

To check it says on their website to insert a suitable tool (no pointy tip) into the ball and push hard.

When there is strong resistance after a little less than an inch (2cm), the accumulator still holds a charge and is probably repairable. When it is possible to insert the tool almost all the way, there is no charge and the diaphragm is probably gone.

It is not a 100% certain test, as even with no nitrogen charge when tested, the accumulator might still hold a new charge.

 

 

Thanks for posting the link to their website. Although I can't comprehend much on their website, I do agree with using the  tool to check the condition of the diaphragm. We have discussed it before on the forum. We consider it to be a good "field test" if you are looking for an accumulator in a salvage yard. The test won't tell you how good the accumulator pre-charge pressure is but if it doesn't pass the test with the tool, you will know for sure that t is bad. Below are photos I took when we were discussing it on the forum.

[2seater]

The pressure relief I referred to is the manual valve I use to control and release the fluid when testing on the bench. My choice of words was unfortunate. I also use the gauge and drain valve on the car to do the same tests where I can let it return to the reservoir and circulate as much fluid as desired.

 

I know the check valve referred to, and while I have never actually tried removing it, I have uncapped it to look inside. It could probably be uncapped to purge air if done very carefully by bumping the pump motor momentarily but I have never tried this, so the result is unknown. I would like to try that but I am out of state for the eclipse.

[Aztec62]

Anybody have a known-good-and-tested Motor/Pump/Brake fluid reservoir assembly for sale?

I might be able to fix the pump sooner or later, but the filter in the reservoir of my Reatta is clogged anyway and there is no way to clean or replace it.

[DAVES89]

I have three of them. The test I run is I put 12 volts to the pressure switch. If it runs and squirts I call it "good". Is that a "good" test in your opinion? My normal price is $195.00 delivered in the continental US. How expensive and difficult to send to Germany?

 It also will include a known good switch, but a weak accumulator ball.

[Ronnie]

Henning, If you are interested in the parts Dave has for sale - I can vouch for Dave's honesty and integrity. You can count on Dave doing what he says he will do. I have purchased several parts from him that he shipped to me and he has even delivered parts to my door when he was traveling on vacation. You can buy with confidence from Dave.

[DAVES89]

The pump/motor assemblies do not have the resivoir connected to them, however it doesn't look to be difficult to remove a tank out in the yard. I will grab one if that is what you need. Let me know what test you want me to run for the resivoir. I do know that when I cut the hose to remove the pump/motor the fluid just rushes out [gravity feed].