Brakes, Clutch & Hydraulics

[Lee_FR140]

Evening Folks,

Looking for some help..

From time to time, the car feels like the rear calipers are not releasing fully causing it to feel sluggish. When this happens, the handbrake also feels like it has somewhat less resistance when pulled.
Coincidentally, when this happens, the clutch pedal feels like it's gone soft but when pulling away from stationary, it makes a screeching noise (as if it's not fully engaged).

Earlier on, I took car out and everything felt normal - no drag, handbrake had plenty of resistance and clutch pedal was solid and everything engaged as you'd expect. This appears to be chance it has not happened however.

Trying to find the root cause of this intermittent arse-ache...

• Sticky Rear Calipers?
• ABS Sensor or Brake Servo?
• Master/Slave Cyl for Clutch?

As a side note, it was doing this a while ago and I had the rear pads and the brake fluid changed - afterwards the car drove as new which made me think it was a pressure issue with the caliper pistons..

Any Ideas / Anyone on here well versed with Hydraulics and Brake/Clutch systems?

Cheers,

Lee

 

[Lee_FR140]

Quick Nudge on this..?!

 

[everson38]

Evening Folks,

Looking for some help..

From time to time, the car feels like the rear calipers are not releasing fully causing it to feel sluggish. When this happens, the handbrake also feels like it has somewhat less resistance when pulled.
Coincidentally, when this happens, the clutch pedal feels like it's gone soft but when pulling away from stationary, it makes a screeching noise (as if it's not fully engaged).

Earlier on, I took car out and everything felt normal - no drag, handbrake had plenty of resistance and clutch pedal was solid and everything engaged as you'd expect. This appears to be chance it has not happened however.

Trying to find the root cause of this intermittent arse-ache...

• Sticky Rear Calipers?
• ABS Sensor or Brake Servo?
• Master/Slave Cyl for Clutch?

As a side note, it was doing this a while ago and I had the rear pads and the brake fluid changed - afterwards the car drove as new which made me think it was a pressure issue with the caliper pistons..

Any Ideas / Anyone on here well versed with Hydraulics and Brake/Clutch systems?

Cheers,

Lee

Hey Lee

Regarding your issue. This seems likes it is going be a process of elomination. With the calipers sticking changing the pads would not really he the issue. It would be.more to do with calipers them selves. Either stuck slider pins or a seized caliper which in turn would cause brakes not to work and giving you sticking effect. Now you would hope if u went to the garage they would of alongside changing brakes, they grease up your slider pins and noticed if your calipers we having issues. I.e piston not retracting properly. But again if you just went for brakes they may have literally just done that. So I would start at the checking the.calipers. not top sure the link with brakes and clutch other than the brake fluid used is the same but you have changed that. But inspect you brake reservoir and see if it is leaking or level is low indicating a possible leak or an internal leak. These are Al things you can check without spending any money.

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[Lee_FR140]

Hey Lee

Regarding your issue. This seems likes it is going be a process of elimination. With the calipers sticking changing the pads would not really help the issue. It would be more to do with calipers them selves. Either stuck slider pins or a seized caliper which in turn would cause brakes not to work and giving you sticking effect. Now you would hope if u went to the garage they would of alongside changing brakes, they grease up your slider pins and noticed if your calipers we having issues. I.e piston not retracting properly. But again if you just went for brakes they may have literally just done that. So I would start at the checking the calipers. not too sure the link with brakes and clutch other than the brake fluid used is the same but you have changed that. But inspect you brake reservoir and see if it is leaking or level is low indicating a possible leak or an internal leak. These are Al things you can check without spending any money.

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Thanks for the reply - appreciated.

the brake fluid used is the same but you have changed that.

They drained some of the old fluid and checked the calipers - it wasn't a full flush (more to try and see if the fluid was a significant part of the problem) and there was a mention of slider pins being greased.

In my mind, if something has 'seized', it wouldn't be intermittent - it would be a permanent problem until resolved.

inspect you brake reservoir and see if it is leaking or level is low indicating a possible leak or an internal leak.

Fluid Reservoir appears to be well sealed and holds fluid without issue.

not too sure the link with brakes and clutch other than the brake fluid used is the same but you have changed that.

My thought was that if the calipers are stuck on, it's drawing more fluid to that area of the system thus reducing it from another area, but as i'm not a Hydraulics engineer and don't know what the system layout is (other than sharing a common fluid reservoir), I couldn't say for sure.

An interesting thing I noticed was that when stopped, if I fully press the brake pedal and then engage hand brake a few times, everything feels spot on which leads me to think it's a piston not fully retracting - knackered caliper/calipers?!

 

[Legojon]

An interesting thing I noticed was that when stopped, if I fully press the brake pedal and then engage hand brake a few times, everything feels spot on which leads me to think it's a piston not fully retracting - knackered caliper/calipers?!

That's pretty much what happened to my Cupra. Initially I could tell a caliper was dragging because I couldn't pull the handbrake lever up as much as usual. I pressed the brake pedal hard a couple of times and released it and it let go. In the end, I had a new rear caliper and it made the other side drag. So I had to have a rear caliper the other side as well.

 

[Lee_FR140]

In the end, I had a new rear caliper and it made the other side drag. So I had to have a rear caliper the other side as well.

Cheers for the reply - do you know if a strip down and service would resolve the issue also? Or, is it likely more cost effective just to supply & fit 2x new calipers?

I suspect I know the answer already...

 

[everson38]

Cheers for the reply - do you know if a strip down and service would resolve the issue also? Or, is it likely more cost effective just to supply & fit 2x new calipers?

I suspect I know the answer already...

If your doing the work yourself then the strip down would be cheaper but at little more.time consuming. If your taking your car to a garage I would have then replace calipers just because it's easier for them and less chance for them to rush the job as they are a business at the end if day so corners. Maybe cut i.e seating the piston boot correctly etc.

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[Lee_FR140]

If your doing the work yourself then the strip down would be cheaper but at little more.time consuming. If your taking your car to a garage I would have then replace calipers just because it's easier for them and less chance for them to rush the job as they are a business at the end if day so corners. Maybe cut i.e seating the piston boot correctly etc.

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Thanks for the reply (and apologies for the late thanks!!)

I'm still trying to work out the correlation between the Brakes dragging and the clutch issue (as mentioned up above).

Is there a chance the 2 are linked or is it more likely that it's coincidental?

TIA

- Lee

 

[Lee_FR140]

@everson38 @RUM4MO You guys seem to contribute quite a bit so perhaps you'll know (or maybe not!!) - do either of you know if the hydraulic drawings for the Ibiza's ever made it to the internet? It would be interesting to see these..

 

[everson38]

@everson38 @RUM4MO You guys seem to contribute quite a bit so perhaps you'll know (or maybe not!!) - do either of you know if the hydraulic drawings for the Ibiza's ever made it to the internet? It would be interesting to see these..

I'm not too sure about this unfortunately. Also thinking maybe an abs issue. If the abs module aka Abs pump isn't providing enough flow of brake fluid, it could be building up some back pressure. The same for the brake master cylinder?

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[RUM4MO]

This sort of thing should not be difficult to sort out if approached in a sensible/logical way by a professional mechanic, the hydraulics on these cars are not any different to those on most other cars. I'd expect any restriction being caused by the ABS would either show up as a logged fault on the ABS system as it runs a self test every time the car is started and moved, or when a mechanic was "doing things" with the brake fluid.

These rear callipers have a built in return spring but in the past I, have found that they can fail and cause the handbrake piston adjustment to wind out too far and so that car needed the piston retracted every month to get rid of brake drag, so I just fitted external lever return springs, if I had taken it into the VW dealership they would have replaced the calliper under warranty, but I did not want to waste my day time messing around with dealership workshop visits. Fitting external return springs from a Sharan etc MK1 sorted that issue out until we traded that Polo in at 13 years old.

Edit:- just to make it clear, on the Polo I mentioned, the rear brake on one side was getting warmer than the other side, on inspection, the wheel was stiff to rotate, I found that by retracting the piston fully this problem would go away initially then return slowly over a period of a month - if this is the root cause of your problem, you could buy a piston retracting tool and do that job yourself.

 

[everson38]

This sort of thing should not be difficult to sort out if approached in a sensible/logical way by a professional mechanic, the hydraulics on these cars are not any different to those on most other cars. I'd expect any restriction being caused by the ABS would either show up as a logged fault on the ABS system as it runs a self test every time the car is started and moved, or when a mechanic was "doing things" with the brake fluid.

These rear callipers have a built in return spring but in the past I, have found that they can fail and cause the handbrake piston adjustment to wind out too far and so that car needed the piston retracted every month to get rid of brake drag, so I just fitted external lever return springs, if I had taken it into the VW dealership they would have replaced the calliper under warranty, but I did not want to waste my day time messing around with dealership workshop visits. Fitting external return springs from a Sharan etc MK1 sorted that issue out until we traded that Polo in at 13 years old.

Edit:- just to make it clear, on the Polo I mentioned, the rear brake on one side was getting warmer than the other side, on inspection, the wheel was stiff to rotate, I found that by retracting the piston fully this problem would go away initially then return slowly over a period of a month - if this is the root cause of your problem, you could buy a piston retracting tool and do that job yourself.

Sounds like a good place to start. What is am external lever return spring. I've tried typing that in and it's bring things up about door handles lol. If he wants to follow someone on YouTube what job would he be looking to type in to find this process being carried out.

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[RUM4MO]

Well stuffing into Google "vw rear calliper hand brake lever return spring" worked for me a minute ago.

One but very expensive source:- https://www.darksidedevelopments.co...brake-caliper-return-springs-7h0-615-296.html

Edit:- what I fitted this time round was :- 7M0 615 295 (from 1998 Sharan) for LHS + 7M0 615 296 (from 1998 Sharan) for RHS.

As for doing/needing a youtube video guide for every job - that could lead to disaster, most times you need to have the ability to work these things out to be able to do brake jobs safely.

 

[Lee_FR140]

Cheers for the input both - appreciate it. I agree, it shouldn't be a difficult fix however the last garage that looked at it suggested it was likely a sticky caliper but "weren't sure" because it was intermittent...

The car is in on Friday for the timing belt so I'm going to ask the mechy to have a look afterwards.

Interestingly, if I park in a way that applies load to the rear brakes, i.e on a hill, when the brakes are released, they release completely free. It's normally after a bit of driving where they start to feel "sticky".

I know this sounds stupid but I just can't work out if the "screech" from the clutch and the sticking brakes are related - my reason being that if I Stop, Pull the handbrake on and depress the brake pedal, and then let handbrake down again, and pull away, there's no noise. It's almost as if when the caliper sticks, it draws fluid away from other areas so the clutch doesn't have as much pressure....

Lets see what Friday brings.

Thanks again both..

 

[everson38]

Cheers for the input both - appreciate it. I agree, it shouldn't be a difficult fix however the last garage that looked at it suggested it was likely a sticky caliper but "weren't sure" because it was intermittent...

The car is in on Friday for the timing belt so I'm going to ask the mechy to have a look afterwards.

Interestingly, if I park in a way that applies load to the rear brakes, i.e on a hill, when the brakes are released, they release completely free. It's normally after a bit of driving where they start to feel "sticky".

I know this sounds stupid but I just can't work out if the "screech" from the clutch and the sticking brakes are related - my reason being that if I Stop, Pull the handbrake on and depress the brake pedal, and then let handbrake down again, and pull away, there's no noise. It's almost as if when the caliper sticks, it draws fluid away from other areas so the clutch doesn't have as much pressure....

Lets see what Friday brings.

Thanks again both..

Yeah see what your mechanic says but just be aware if u want an in depth look you may need to book it in for a proper once over. Cz if u r having timing belt done (well done for looking after it btw) if u try to add in would mind looking at brakes quickly for me. It may not get the thorough checking you want. I know annoying to have to book again and maybe pay for a once over for nothing to come back. But a quick 10 mn inspection may save you money but if it continues to happen you may be always wondering

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[Lee_FR140]

Yeah see what your mechanic says but just be aware if u want an in depth look you may need to book it in for a proper once over. Cz if u r having timing belt done (well done for looking after it btw) if u try to add in would mind looking at brakes quickly for me. It may not get the thorough checking you want. I know annoying to have to book again and maybe pay for a once over for nothing to come back. But a quick 10 mn inspection may save you money but if it continues to happen you may be always wondering

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I'll call them tomorrow. They seem to be a well thought of place.

Cheers for the input!

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