Dark Comfortmatic Clutch fluid

[Meg and Sue]

The clutch fluids dark even though it has been replaced recently.
1. What is the cause?
2. Will it eventually lead to master cylinder failure?

Many thanks

 

[Figaro]

I'd be inclined to ask whoever changed the hydraulic fluid recently why it's discolored.

 

[Burge]

"I believe it should be Dexron 111 Automatic Transmission
Fluid Red in Colour.
Comfortmatic Gearbox Problems

There seems to be a lot of anxiety about the reliability of Comfortmatic gearb
misinformation floating around the web (and here)

The Comfortmatic system performs the operations your left foot or left hand (
vans) would usually perform in a manual van.

The gearbox and clutch in both the manual and Comfortmatic vehicles are ide
only occur in how the gear selector is operated and how the clutch master cyli

Gear Selection

The gear selector cam on a manual gearbox is operated by cables directly con
lever to provide the up/down and rotations required to select the 6+R different
Comfortmatic system the gear selector cam is operated by 2 actuators operate
solenoids in the Comfortmatic hydraulic module. 3 solenoids are required to r
of the 6+R manual cable operations. All of these gear selection operations are
gearbox so it doesn't know, or care what is actually changing gears inside the

The Comfortmatic hydraulic gear selector module is very reliable , the only fa
occasional cracked solenoid casings. These can be sourced and replaced but g
replace the whole unit just in case (and it's not their money).

Gear Selection system Durability

The fluid used in this gear selector module is Dexron III Automatic Transmis
red fluid in the rectangular reservoir on the top of the gearbox. The module ha
that captures any minor fluid weepage past seals and recirculates it back into
reused. The system has a very easy life by hydraulic standards and no parts w
should get used so it is effectively sealed for life and needs no maintenance. T
4th solenoid that feeds the clutch actuation system does not have a scavenge sy

Clutch Actuation

The clutch actuation in the Comfortmatic system is the same as the manual cl
cylinder is operated by hydraulics rather than the organic blob holding the ste

On a manual clutch when you press the pedal this pushes a pushrod in the clut
send fluid under pressure to the slave cylinder. With the Comfortmatic the 4th
selector module provides the hydraulic pressure to the Master/Slave unit to m
pedal pushrod operation."

I copied that off Google

 

[Lenny HB]

I believe it should be Dextron 111 and Red in Colour.

I hope not that would completely bugger it that is ATF.

 

[Lenny HB]

Sounds like you could have a slave cylinder problem and getting cross contamination with the hydraulic fluid & actuator fluid.

I don't know if a dealer is able to aynalise the fluid otherwise may mean gearbox out to check the cylinder.

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[MisterB]

"I believe it should be Dexron 111 Automatic Transmission
Fluid Red in Colour.
Comfortmatic Gearbox Problems

There seems to be a lot of anxiety about the reliability of Comfortmatic gearb
misinformation floating around the web (and here)

The Comfortmatic system performs the operations your left foot or left hand (
vans) would usually perform in a manual van.

The gearbox and clutch in both the manual and Comfortmatic vehicles are ide
only occur in how the gear selector is operated and how the clutch master cyli

Gear Selection

The gear selector cam on a manual gearbox is operated by cables directly con
lever to provide the up/down and rotations required to select the 6+R different
Comfortmatic system the gear selector cam is operated by 2 actuators operate
solenoids in the Comfortmatic hydraulic module. 3 solenoids are required to r
of the 6+R manual cable operations. All of these gear selection operations are
gearbox so it doesn't know, or care what is actually changing gears inside the

The Comfortmatic hydraulic gear selector module is very reliable , the only fa
occasional cracked solenoid casings. These can be sourced and replaced but g
replace the whole unit just in case (and it's not their money).

Gear Selection system Durability

The fluid used in this gear selector module is Dexron III Automatic Transmis
red fluid in the rectangular reservoir on the top of the gearbox. The module ha
that captures any minor fluid weepage past seals and recirculates it back into
reused. The system has a very easy life by hydraulic standards and no parts w
should get used so it is effectively sealed for life and needs no maintenance. T
4th solenoid that feeds the clutch actuation system does not have a scavenge sy

Clutch Actuation

The clutch actuation in the Comfortmatic system is the same as the manual cl
cylinder is operated by hydraulics rather than the organic blob holding the ste

On a manual clutch when you press the pedal this pushes a pushrod in the clut
send fluid under pressure to the slave cylinder. With the Comfortmatic the 4th
selector module provides the hydraulic pressure to the Master/Slave unit to m
pedal pushrod operation."

I copied that off Google

I'm not so sure there are lots of misinformation floating around on here relating to comformatic gearboxes ..... Unless you're referring to your own post of course ...

 

[Burge]

Sorry if I've misinformed......was only looking for help so Googled "Comfortmatic G/box" posted what I read..... if this info is incorrect please ignore .

 

[WESTY66]

If you google comfortmatic faults it should say “Go straight to Adams Moray, Portsmouth”

 

[Pausim]

Adams Morey told me that dark clutch actuation fluid means trouble ahead, having reassured me that mine was ok and clear when they drained it off. dunnah01 has over the years posted some helpful diagrams and pictures of the Comfortmatic Master/Slave cylinder. My simple understanding is that this unit has separate chambers and different hydraulic fluids are used for the clutch and gear selection parts of the unit. If the dark gear selection fluid gets into the lighter clutch fluid you have a serious problem. I also recall that some unorthodox methods of replacing the clutch activation fluid can cause problems, for example vacuum emptying can not only suck the lighter clutch fluid out but draw the gear fluid past the seals to pollute the clutch fluid.

What this amounts to is it is important that the Comfortmatic servicing is done by someone who really understands the system and knows how to drain and reset it properly.

 

[Badknee]

My comfomatiic fluid was very dark last year so I’m having it changed again on our way to the Santander boat to check it.

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[Meg and Sue]

My comfomatiic fluid was very dark last year so I’m having it changed again on our way to the Santander boat to check it.

What year and milage was on your motorhome when you first had the fluid {dot 4} changed?
Has the new fluid got darker since it was fitted?

I believe it is recommended to be chamged every 2 years

 

[Meg and Sue]

I'd be inclined to ask whoever changed the hydraulic fluid recently why it's discolored.

It was myself!!!!

 

[rb62]

A very risky procedure to carry out yourself unless you have the correct software program that puts the clutch through 15 cycles to ensure all the air is bled out and then adjusts the kiss point.

Comfortmatic Fluid Changes

I use a busy local mechanic who I trust to do cambelt changes etc, I know he doesn’t see many comfortmatic systems though and I want my fluids changed. Are the fluid changes easy enough for competent independent mechanics or is it something that should be left to Fiat Professionals familiar...

www.motorhomefun.co.uk

 

[MisterB]

To add further to the discussion, if the fluid is discoloured, will the repair be as expensive to have the seals replaced as soon as possible in comparison to suffering a complete failure? Is damage caused to such an extent that a new gearbox is required as opposed to the replacement of seals (though I know the labour costs and time involved even for an just replacement seals will not be 'cheap').

I am not advocating not having repairs done in a timely manner and I also recognise the inconvenience and additional costs in recovery from wherever the failure occurs.

We had our, thankfully clear fluid replaced 18 months ago and will be having it replaced again next year!

 

[Kannon Fodda]

To add further to the discussion, if the fluid is discoloured, will the repair be as expensive to have the seals replaced as soon as possible in comparison to suffering a complete failure? Is damage caused to such an extent that a new gearbox is required as opposed to the replacement of seals (though I know the labour costs and time involved even for an just replacement seals will not be 'cheap').

I am not advocating not having repairs done in a timely manner and I also recognise the inconvenience and additional costs in recovery from wherever the failure occurs.

We had our, thankfully clear fluid replaced 18 months ago and will be having it replaced again next year!

The gearbox itself doesn't fail, it's the actuator systems that operate the clutch. The Comfortmatic system is effectively a manual gearbox and clutch that the servos and actuators are all robotically operated.

Usually when the clutch fluid is contaminated the slave cylinder in the clutch housing starts to leak risking contamination of the clutch plate, or the clutch simply fails to operate as the cylinder has gummed up.

But contamination shows the seals also have failed in the master servo form unit where both the clutch and gear change hydraulics are initiated. It's this form seal breakdown that is the cross contamination of the different clutch and hydraulic fluids. But as far as I know there is no service kit to renew those seals, hence the expensive replacement of the entire form.

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[DDJC]

It was myself!!!!

Mega brave of you!!

 

[DDJC]

I took the advice of the forum, and went to Adam Morey in Portsmouth.
Not cheap, but it is apparently essential to get every part of the drain/refil/bleed done.
A yardstick is that I phoned three motorhome workshops and all of them said they wouldn't touch a comfortmatic fluid change.

 

[gus-lopez]

I think that the OP is talking about the clutch fluid that is combined with the brake master cylinder as they have stated "Dot4" & it actuates the thrust bearing slave cylinder.This can become discoloured if the WHOLE brake system is not also changed .
The OP isn't talking about the comfortomatic system actuation fluid.

What year and milage was on your motorhome when you first had the fluid {dot 4} changed?

 

[D4RR3N]

Are you sure that the system was drained and flushed through completely and the garage didn't just suck out the reservoir and refill it?

 

[rb62]

Are you sure that the system was drained and flushed through completely and the garage didn't just suck out the reservoir and refill it?

see post #12

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[dunnah01]

If anybody has a scrap Master cylinder unit from a Comfortmatic I may be able to put together a repair kit. It's the part that sits with the main Comfortmatic unit above the gearbox. This is what sometimes fails and causes cross contamination and darkening of the clutch actuation fluid and eventual clutch CSC failure (like most modern manual gearboxes the CSC is the part buried inside the clutch bellhousing that needs the gearbox to be removed to change it)

 

[rupert]

see post #12

The fluid is dark cos u didn’t get all the old stuff out if its combind with the brake fluid do it again and brakes at the same time and don’t panic

 

[rb62]

The fluid is dark cos u didn’t get all the old stuff out if its combind with the brake fluid do it again and brakes at the same time and don’t panic

The comfortmatic clutch reservoir is separate from the brakes and only takes 50ml.

 

[rupert]

RHD is separate. LHD is combined brake and clutch reservoir

 

[MisterB]

The gearbox itself doesn't fail, it's the actuator systems that operate the clutch. The Comfortmatic system is effectively a manual gearbox and clutch that the servos and actuators are all robotically operated.

Usually when the clutch fluid is contaminated the slave cylinder in the clutch housing starts to leak risking contamination of the clutch plate, or the clutch simply fails to operate as the cylinder has gummed up.

But contamination shows the seals also have failed in the master servo form unit where both the clutch and gear change hydraulics are initiated. It's this form seal breakdown that is the cross contamination of the different clutch and hydraulic fluids. But as far as I know there is no service kit to renew those seals, hence the expensive replacement of the entire form.

Thanks Rob, but do you know if replacing that master servo kit when it shows signs of contamination (and the oils if course) would negate the need for a new clutch etc and therefore reduce cost and likelihood of total failure ( I know you've been through that scenario so you may know more than most)? I had my fluid changed 18 months ago (totally clear of contamination), based on your experience and am planning to have it replaced early next year, so hoping to avoid the issue completely.... So it's more if a general enquiry rather than an issue I am facing

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[Kannon Fodda]

Usually once contamination has caused the master form unit to fail necessitating that being replaced there will have been damage to the slave cylinder too. Getting to that slave cylinder means you expose the clutch itself so for many it will be cost effective to redo the clutch plate whilst exposed.

In my case the clutch plate had failed as the incorrect operation of failing cylinders no doubt meant it wasn't being opened / closed fully. The notorious Fiat plastic thrust bearings things broke. So my clutch plate had to be changed but they avoided doing the dual mass flywheel part as at only 17,000 miles that should have had plenty of life left.

So really what needs to be done should depend on individual damage found and cost economics on future risk.

Prevention must be better than cure and I now ensure my Comfortmatic clutch Dot4 type fluid is being regularly changed to reduce that contamination risk.

 

[Meg and Sue]

I think that the OP is talking about the clutch fluid that is combined with the brake master cylinder as they have stated "Dot4" & it actuates the thrust bearing slave cylinder.This can become discoloured if the WHOLE brake system is not also changed .
The OP isn't talking about the comfortomatic system actuation fluid.

Its a 2015 Ducato with 36000km and the Dot 4 fluid was changed earlier this year for the first time

 

[Meg and Sue]

Its a 2015 Ducato with 36000km and the Dot 4 fluid was changed earlier this year for the first time

Sorry 2018 Ducato

 

[Meg and Sue]

To add further to the discussion, if the fluid is discoloured, will the repair be as expensive to have the seals replaced as soon as possible in comparison to suffering a complete failure? Is damage caused to such an extent that a new gearbox is required as opposed to the replacement of seals (though I know the labour costs and time involved even for an just replacement seals will not be 'cheap').

I am not advocating not having repairs done in a timely manner and I also recognise the inconvenience and additional costs in recovery from wherever the failure occurs.

We had our, thankfully clear fluid replaced 18 months ago and will be having it replaced again next year!

Are seals available as "spare parts"

 

[Meg and Sue]

Are you sure that the system was drained and flushed through completely and the garage didn't just suck out the reservoir and refill it?

The system was drained fully and flushed as part of the release bearing replacement. The next time 3 months later it was only the reservoir that was sucked out.