Technical Punto Evo ABS pump

[RMVS]

Hi folks quick question.

I think the ABS pump is faulty in a 2010 Punto Evo. Trouble is someone has been messing about with the car before we got it so not sure if the correct ABS pump is in vehicle and can’t find the correct part numbers anywhere online.

My question is. If the pump at scrap yard has same electronic plug do the numbers matter or can I take a pump out any Punto Evo around same year with same plug?

Thanks

 

[The Panda Nut]

I am not certain, but as there is an ECU involved its likely that you would need an identical unit. I also suspect if you get a unit from car of the same year of manufcture you would be OK with it, but it would be a gamble. Why not ring your local Fiat dealer and ask the workshop foreman. Why do you think the ABS unit is faulty. You need a diagnostic check to confirm this. Just pulling it out could be a waste of time and money. ALso ask aroudn for people who repair these as this might be cheaper.

 

[bugsymike]

It's always a nightmare putting right someone else's "work"

 

[RMVS]

I am not certain, but as there is an ECU involved its likely that you would need an identical unit. I also suspect if you get a unit from car of the same year of manufcture you would be OK with it, but it would be a gamble. Why not ring your local Fiat dealer and ask the workshop foreman. Why do you think the ABS unit is faulty. You need a diagnostic check to confirm this. Just pulling it out could be a waste of time and money. ALso ask aroudn for people who repair these as this might be cheaper.

Thanks for reply.

Got the car a few weeks ago from auction and the brake pedal was solid. So I replaced the master cylinder and when the master cylinder was off you could hear the servo had vacuum as you pushed the pedal. The pipe between servo and manifold was also changed as someone had tried to bypass the brake sensor. So with it all connected up I then bled all the brakes.

Worth noting the fluid that came out the bottle was green! No fluid came out the 4 outlet pipes at ABS pump but fluid did come out the bleed nipples at each brake. I bled them up with pressure bleeder and the pedal felt good.

It wasn’t until I turned the car on and went back 50 yards then forward 50 yards did the pedal go hard again so I am assuming it’s the pump.

I have a spare pump there off another EVO with different numbers I will give it a try. I can’t think of anything else that would cause the pedal to be hard.

The person that had it before tried an exhaust repair. They tried fitting a 48mm flexi to a 41mm pipe with metal packers in between, no paste and clamps were hand tight. Car was roaring like mad. Couldn’t believe what they had done.

 

[The Panda Nut]

That doesnt really sound right. You will need to bleed the brakes using MES or get a garage to do it to bleed the ABS unit. It sounds more like a servo problem. There is at least one other thread on here relating to solid brake pedal. Ill see if I can find it and point you to that.

ABS unit will work or not work. Working you will get the pulsing pedal and ABS noise under hard braking. Not working you wont get this but the brakes will still feel the same. You will encounter rear wheel lock-up as wel,l as the abs controls this too. If the ABS fails it fails safe and the light willl come on on the dash. If the servo fails you might expect a very hard pedal. Im not sure if you have a diesel there will be a vacuum pump as well and that failing or a hold in its suction pipe to the servo would render the servo inoperable and give a hard pedal. I would also check the suction pipe is mot blocked or damaged before doing anything to ABS. There is a new thread on the Panda forum about checking servo operation. ABS units are generally bomb proof as they have to be on safety grounds.

 

[RMVS]

That doesnt really sound right. You will need to bleed the brakes using MES or get a garage to do it to bleed the ABS unit. It sounds more like a servo problem. There is at least one other thread on here relating to solid brake pedal. Ill see if I can find it and point you to that.

ABS unit will work or not work. Working you will get the pulsing pedal and ABS noise under hard braking. Not working you wont get this but the brakes will still feel the same. You will encounter rear wheel lock-up as wel,l as the abs controls this too. If the ABS fails it fails safe and the light willl come on on the dash. If the servo fails you might expect a very hard pedal. Im not sure if you have a diesel there will be a vacuum pump as well and that failing or a hold in its suction pipe to the servo would render the servo inoperable and give a hard pedal. I would also check the suction pipe is mot blocked or damaged before doing anything to ABS. There is a new thread on the Panda forum about checking servo operation. ABS units are generally bomb proof as they have to be on safety grounds.

I am fine to change the servo first that’s not an issue but couldn’t see any videos on how to do it. Seemed pretty daunting as not done one before. That would save me bleeding all the brakes again also

 

[The Panda Nut]

The basics of changing a servo are not difficult providing you can get access to the bolts, You probably need to disconnect the brake pedal / master cylinder link rod and then remobe the aster cylinder teh servo should be held on by 3 or 4 nuts from inside on the bulkhead and should lift out once all the gubbins is out of the way. The servo should hold vacuum for a while after the engine is switched off. If you switch off and then pres teh footbrake you should feel teh servo effect for 3 to 5 pushes of teh brake pedal, after which the pedal will become hardermand it wont push down as far. If your brake pedal does not behave like this it suggests a servo issue. If in doubt you should get a nechanic to help. Brake work is one of the less expensive things to pay for!

 

[RMVS]

The basics of changing a servo are not difficult providing you can get access to the bolts, You probably need to disconnect the brake pedal / master cylinder link rod and then remobe the aster cylinder teh servo should be held on by 3 or 4 nuts from inside on the bulkhead and should lift out once all the gubbins is out of the way. The servo should hold vacuum for a while after the engine is switched off. If you switch off and then pres teh footbrake you should feel teh servo effect for 3 to 5 pushes of teh brake pedal, after which the pedal will become hardermand it wont push down as far. If your brake pedal does not behave like this it suggests a servo issue. If in doubt you should get a nechanic to help. Brake work is one of the less expensive things to pay for!

Sorry if I am being daft here but if it was a vacuum issue ie servo why was the pedal pushing down no problem before I put the Dot 4 in ie when the system was empty. Surely the vacuum would still work the same

 

[The Panda Nut]

If the system is empty the pedal will go down easy, or if there is a lot of air in it the pedal will move easily. The servo will not have such a notable effect. Once the system is full of fluid and free of air there is resistance in the lines and more resitance if anything is stuck or seized and this will be much more apparent. If the servo does not work the pedal will be effectively much harder.

 

[bugsymike]

Is it possible given that the fluid that came out was green that it may not have been brake fluid and has knackered the brake hydraulics.
Many years ago we had a customer with nearly new Rover 2000 who decided to top up his brake fluid using engine oil!!! Massive damage to his braking system.
Any ABS faults should light up to speedo with error messages/codes normally.
Re green fluid is it possible they used Citroen LHM fluid for older models which is green , but definitely not compatible with DOT 4 etc.

 

[RMVS]

Is it possible given that the fluid that came out was green that it may not have been brake fluid and has knackered the brake hydraulics.
Many years ago we had a customer with nearly new Rover 2000 who decided to top up his brake fluid using engine oil!!! Massive damage to his braking system.
Any ABS faults should light up to speedo with error messages/codes normally.
Re green fluid is it possible they used Citroen LHM fluid for older models which is green , but definitely not compatible with DOT 4 etc.

Getting no ABS lights which is the only doubtful thing about the ABS module. I will take a video tomorrow morning and upload it

 

[AndyRKett]

Is it possible given that the fluid that came out was green that it may not have been brake fluid and has knackered the brake hydraulics.
Many years ago we had a customer with nearly new Rover 2000 who decided to top up his brake fluid using engine oil!!! Massive damage to his braking system.
Any ABS faults should light up to speedo with error messages/codes normally.
Re green fluid is it possible they used Citroen LHM fluid for older models which is green , but definitely not compatible with DOT 4 etc.

I had someone in a quick fit do this to my car many years ago. helpfully topped up the brake fluid with some unknown hydraulic fluid and it could not handle the temperatures in the brakes so you would brake then the fluid would heat up, expand and then the car would bring itself to a stop, then you'd not be able to move it till the brakes cooled down again. you'd maybe manage another mile or so and then the car would not move again.

I was lucky I got a specialist company to that particular make and model to replace the whole braking system with parts off another car. cost me about £300 but better than the £1000 that quick fit quoted while of course denying any liability for the damaged they'd caused.


In this instance I would probably flush the brakes through several times with loads of clean brake fluid to make sure that I got anything out that should not be in there.

 

[bugsymike]

Getting no ABS lights which is the only doubtful thing about the ABS module. I will take a video tomorrow morning and upload it

Hopefully get no ABS codes/lights, but that is just the computer side of the ABS, if the pumping/valve side is jammed up with the wrong fluid you may still have an issue there.
May be irrelevant but I have heard of people online just changing the electrical or the mechanical side of a ABS unit, though you have to be aware of any safety implications.!!!

 

[RMVS]

Hopefully get no ABS codes/lights, but that is just the computer side of the ABS, if the pumping/valve side is jammed up with the wrong fluid you may still have an issue there.
May be irrelevant but I have heard of people online just changing the electrical or the mechanical side of a ABS unit, though you have to be aware of any safety implications.!!!

 

[RMVS]

I am going to take a video in about an hour and put the link in here see what folks thoughts are of changing the servo or pump first. As I said I have a spare pump out a ten plate Evo just different numbers. Would only take 45 mins to change and bleed again as nipples have already been off

 

[bugsymike]

I am going to take a video in about an hour and put the link in here see what folks thoughts are of changing the servo or pump first. As I said I have a spare pump out a ten plate Evo just different numbers. Would only take 45 mins to change and bleed again as nipples have already been off

Yes, I would try as a unit first, always better than disturbing it.
Re the pedal solid bit, were the brakes binding/staying on, in that if you opened a union the pedal would go down and the brakes free off or just a funny pedal/hard pedal but brakes worked but not stopping well?

 

[RMVS]

Yes, I would try as a unit first, always better than disturbing it.
Re the pedal solid bit, were the brakes binding/staying on, in that if you opened a union the pedal would go down and the brakes free off or just a funny pedal/hard pedal but brakes worked but not stopping well?

The car drove from auction and did brake but the pedal was solid and hard to push. On the video I will test opening a union to see if it goes soft. What union would you recommend? One of the two from master cylinder or one going to a wheel? If it goes soft what would this suggest for you?

Thanks

 

[bugsymike]

The car drove from auction and did brake but the pedal was solid and hard to push. On the video I will test opening a union to see if it goes soft. What union would you recommend? One of the two from master cylinder or one going to a wheel? If it goes soft what would this suggest for you?

Thanks

Releasing a union was more if the brakes were sticking on, rather than just hard. If that was the case the wheels would feel hot from dragging.
When you drove it back was there any sign of binding?
Re the servo side, without moving the car, pump the pedal, it is hard? When you start the engine does the pedal start to feel normal as though the servo is working or hard straight away without even moving the car?
On driving back from auction if brakes worked up to a point and didn't bind it would suggest like you first thought a servo or lack of vacuum issue, as in split pipes/unions or if diesel a poor vacuum pump. Especially if no ABS or other warning lights/codes etc.
I have had cars brought to me with a hard pedal and brakes sticking on caused by something as simple as a wire dropped across the brake pedal or a brake light switch badly fitted causing the brake pedal not to come right back, so that after a short drive the brakes lock on because the master cylinder cannot release the pressure by the piston inside being allowed to come right back.

 

[RMVS]

Video in link below

 

[bugsymike]

Thanks for the video, seems plenty of vacuum at the pipe to the servo.
If you run the engine for a few minutes, then switch off for say ten minutes and pull the vacuum pipe out of the servo, can you feel vacuum release as you do it , as in, is the servo air tight and holding the vacuum, it should be hard to pull the pipe out of the servo due to the vacuum holding it in. Some of my vehicles have still got vacuum at the servo the next day! The reason I ask is you have shown vacuum at the pipe but if servo was leaking constantly it may account for the noise you heard at the other end of the pipe near the bulkhead.
Regarding the ABS unit, I have never done this so maybe others will advise against it, but if the electrical plug to the ABS unit was disconnected and providing car was still driveable apart from error messages, if safe to do so does the brake pedal get hard again over the same distance and by the way are we saying a hard pedal but no brakes dragging at the wheels as in jammed on?