Technical Clutch failing - changing the fluid?!

[greypanda]

What happens if you don’t ever replace/change your clutch fluid?

I never ever did this on my old 07 plate Panda (had no problems), but the clutch is failing on my 16 plate 500 (25k miles - unbelievable I know ) and some forums say that the clutch fluid should be changed every 2-3 years. I am unsure what to believe?

I would consider myself knowledgeable ish about my car (certainly not ignorant to things I need to do to keep it running well), but I was certainly flabbergasted yesterday when the clutch went straight to the floor and I couldn’t change gear!

The 500 is in the garage ready for its diagnostics on Monday.

 

[GeoBog]

The clutch fluid on the 500 is actually the brake fluid, both systems share the same fluid and this needs changing at least every 3 years because of its hygroscopic properties. If you never changed the brake fluid it's likely the master or slave cylinder are seized and need replacing. They are known to fail as they are not very good quality.

 

[greypanda]

The clutch fluid on the 500 is actually the brake fluid, both systems share the same fluid and this needs changing at least every 3 years because of its hygroscopic properties.

I thought there were two separate holes for the brake fluid and clutch fluid? So brake fluid is the yellow top on the right and the clutch fluid is the white/clear top on the left. Gutted I never knew either of them required changing.

If you never changed the brake fluid it's likely the master or slave cylinder are seized and need replacing. They are known to fail as they are not very good quality.

Thank you - I will remember this when the garage call me tomorrow. Any tips on stopping it failing in the future? I will definitely be changing the brake and clutch fluid going forwards.

 

[Baglady1990]

I thought there were two separate holes for the brake fluid and clutch fluid? So brake fluid is the yellow top on the right and the clutch fluid is the white/clear top on the left. Gutted I never knew either of them required changing.

Thank you - I will remember this when the garage call me tomorrow. Any tips on stopping it failing in the future? I will definitely be changing the brake and clutch fluid going forwards.

The clutch fluid is the small pot on the drivers side above the air con pump the yellow top one on the passenger’s side is the brake fluid but as mentioned the same dot 4 fluid is used

Again the fluid is hydroscopic so any water ingress will render the fluid useless and won’t operate the master & slave so your clutch won’t work!

 

[greypanda]

Again the fluid is hydroscopic so any water ingress will render the fluid useless and won’t operate the master & slave so your clutch won’t work!

This is a huge eye opener! Thanks so much - this is exactly what has happened I’m sure of it. I had a very small bit of clutch left yesterday (the pedal was on the floor though) - managed to drive it to the garage but it was hard work. Lots of turning the engine off at junctions and traffic lights then putting it in gear before starting. Nightmare!!! If I had known to change the fluids to prevent this I would have done

 

[Baglady1990]

This is a huge eye opener! Thanks so much - this is exactly what has happened I’m sure of it. I had a very small bit of clutch left yesterday (the pedal was on the floor though) - managed to drive it to the garage but it was hard work. Lots of turning the engine off at junctions and traffic lights then putting it in gear before starting. Nightmare!!! If I had known to change the fluids to prevent this I would have done

We all have to learn sooner or later the hydronic system works well if it’s maintained some days it’s weak & problematic but the only issue I’ve ever had was replacing the ageing master & slave cylinders after that no issues at all
Saying that I’m under the bonnet every couple of days checking fluids & keeping my eyes peeled for leaks or smells!

 

[Baglady1990]

Should read some say! Bloody autocorrect

 

[greypanda]

We all have to learn sooner or later

Definitely and I’ve learnt the hard way

the hydronic system works well if it’s maintained some days it’s weak & problematic but the only issue I’ve ever had was replacing the ageing master & slave cylinders after that no issues at all
Saying that I’m under the bonnet every couple of days checking fluids & keeping my eyes peeled for leaks or smells!

Probably worth checking daily … I’m going to start doing this! The hardest to check is the coolant as you can’t actually see through the bottle

 

[Baglady1990]

Definitely and I’ve learnt the hard way

Probably worth checking daily … I’m going to start doing this! The hardest to check is the coolant as you can’t actually see through the bottle

This is true but if you get a torch on one side and look the other you can see for gods sake keep on top of the coolant!!!!!!! If not you could end up with an engine that’s scrap …. Been there done that!

 

[greypanda]

This is true but if you get a torch on one side and look the other you can see for gods sake keep on top of the coolant!!!!!!! If not you could end up with an engine that’s scrap …. Been there done that!

I have a monthly reminder to check my coolant don’t worry hopefully monthly is enough!!!! I clearly need to gen up on my car a bit more.

 

[Baglady1990]

I have a monthly reminder to check my coolant don’t worry hopefully monthly is enough!!!! I clearly need to gen up on my car a bit more.

Yeah just don’t go all neurotic like me

 

[vexorg]

Again the fluid is hydroscopic so any water ingress will render the fluid useless and won’t operate the master & slave so your clutch won’t work!

That's not really true, the clutch would work fine if it was all pure water. Anyone that's had a hydrolocked engine will know how well water compresses.

It's supposed to be more of a problem with the brakes since the force on the fluid can reach much higher pressures, that can displace the water from the fluid, potentially boil the water to steam, then you have no braking force next time round. That's the theory anyway, again unlikely to have any real impact on a road car other than slightly spongey braking.

For a clutch, 'old' fluid will make no real difference for the life of the clutch.

 

[John202020]

Hi I recommend (again) replacing the engine earth strap even at this age a known issue also Iridium plugs.
Yep replace the clutch fluid can be a bit messy look for leaks too try here under the car ?
As for the coolant level, I use my Mazda screen wash level tube, it's a straight plastic tube place in the rad filler pop finger on end withdraw and hold against the side to show the level?
One last pic if you've not found it here's the petrol cap holder!

 

[Baglady1990]

That's not really true, the clutch would work fine if it was all pure water. Anyone that's had a hydrolocked engine will know how well water compresses.

It's supposed to be more of a problem with the brakes since the force on the fluid can reach much higher pressures, that can displace the water from the fluid, potentially boil the water to steam, then you have no braking force next time round. That's the theory anyway, again unlikely to have any real impact on a road car other than slightly spongey braking.

For a clutch, 'old' fluid will make no real difference for the life of the clutch.

Yes I’m sure your right ..with the clutch fluid I’ve noticed that the pot that holds it gets quite warm particularly at the bottom ..does heat affect the fluid at all?

 

[chris3234]

Yes I’m sure your right ..with the clutch fluid I’ve noticed that the pot that holds it gets quite warm particularly at the bottom ..does heat affect the fluid at all?

Yes but at the temps needed to cause issues with it it's likely the plastics housing would start to fail

 

[greypanda]

As for the coolant level, I use my Mazda screen wash level tube, it's a straight plastic tube place in the rad filler pop finger on end withdraw and hold against the side to show the level?

Good idea… would make life easier

One last pic if you've not found it here's the petrol cap holder!

I have found it and use it every time… my old Panda had it too!

 

[jrkitching]

That's not really true, the clutch would work fine if it was all pure water.

It'd work fine for about a week, then corrosion would render both master and slave cylinders scrap.

For a clutch, 'old' fluid will make no real difference for the life of the clutch.

This isn't the case, as the many owners who've had to prematurely replace their clutch hydraulic components will testify.

The absorbed water overwhelms the corrosion inhibitors in the fluid, and once this happens, the steel parts shed tiny rust particles as the pistons slide over the seals. These particles are abrasive and damage the seals, causing them to leak.

When bleeding cars that haven't been regularly maintained, you'll sometimes see old hydraulic fluid that's almost black from the combination of rust and rubber particles.

There's not much fluid in the clutch actuating mechanism, and experience has shown it deteriorates quite quickly on the 500/Panda.

some forums say that the clutch fluid should be changed every 2-3 years. I am unsure what to believe?

I'd agree; it should be changed at least as often as the brake fluid is changed.

 

[jrkitching]

The hardest to check is the coolant as you can’t actually see through the bottle

A cardboard strip makes a great disposable dipstick.

 

[Ralf S.]

There's always a lot of mystique around brake fluid... but it's fairly simple stuff.

It's main job is to transfer pressure from the brake/clutch pedal to the brake caliper or clutch. As Vexorg says, any liquid would do this job.. but some are more suitable than others. Brake fluid works because;

1. It does not corrode ferrous metal;
2. It has a high boiling point (typically 360C)
3. It is "oily"

1. rules out water, 2. rules out antifreeze, engine oil or other fluids you might have lying around in your garage.

Brake fluid is also hygroscopic.. which is a good thing and a bad thing. It dissolves moisture in the system so any condensation etc. in there is no longer able to corrode the brake/clutch system. The capacity for brake fluid to absorb moisture is colossal but eventually the moisture will overwhelm the fluid's ability to dissolve it and the fluid becomes "watery" so that it can start to corrode the brake/clutch system.

Some brake fluids (DOT5, as distinct from DOT 5.1) do not absorb moisture.. and can suffer from water "droplets" in the fluid .. which usually settle in some nook of brake pipe and can then corrode that spot... but DOT3, DOT4 and DOT5.1 dissolve water.

The biggest PITA with dissolved water is that when your brakes (clutch not so much) get hot, they can reach 160-200C .. that makes the water dissolved in the fluid boil. The boiling water releases vapour and then you get "air bubbles" in the system, which degrades the pedal performance (spongey brakes and maybe a big accident, since brakes don't get to 200C just visiting Sainsbury's).

Your failure (pedal not returning) sounds like a clutch slave cylinder failure.. not the clutch itself... The clutch has no contact with the fluid.

The slave contains neoprene seals, which can harden up, or fold in as the piston/rod moves through them and therefore "leak". It's unlikely to be caused by old fluid.. although any corrosion on the piston will cut the seals, as jr says. But the slave seals are 5-6 years old and low mileage .. so maybe the car has done a lot of town use (which means changing gear a lot, and a lot of piston-to-seals action). In addition, the rubber boot over the piston may have perished a bit and has let dirt/moisture into the rod, corroded the rod from the outside side.. and that "grit" has cut the slave seals. My bet is more the latter, since it's outside the car.

Anyhow, change the slave (you may see a leak of fluid dripping down the front of the gearbox) and put all new DOT4 in the clutch circuit (small pot on the left of the engine bay) ... and while you're there... change the brake fluid as well. It'll take a young fella with a rubber tube and a milk bottle aboot 20mins.


Ralf S.

 

[John202020]

It's possible to replace the slave only using the original pipe often the new one will come with a new pipe section attached.