fluid leaking bad! coming from clutch slave or GB? help!

revhead · Postby **revhead** » Mon Mar 04, 2013 3:15 pm

Ok so I knew I had a small leak of some sort and it looked like it was coming from the clutch slave cylinder so I thought it might be an old seal that has perished so I booked it in to the mechanics to suss it out. Today was a nice day so I though a drive was in order so I warmed the car up like usual and I decided to look under the car just to double check this leak and... There was oil everywhere and a pretty constant dripping coming from the clutch slave cylinder side of the gear box!! Looked like a pulsing drip, like a pump building pressure and the oil coming out, then a pause, then another wave of oil drip, then a pause etc.. Didn’t look like a gravity fed drip.

I had a closer look and noticed the boot of the clutch slave cylinder looked dry and that the oil was actually leaking down the clutch fork and onto the floor. I then noticed that oil was dripping from the top of the square shaped rubber boot that is attached to the transmission and goes around the clutch fork. So oil is coming through the top side of this square rubber boot, dripping onto the clutch fork and then onto the ground.

What is the problem here? Is this clutch fork boot perished? Is it still the clutch slave doing this? Is it gear box oil pushing its way out? Help please, I’m worried about driving it to the mechanics now because I don’t want to all of a sudden have no GB oil! Would rather my clutch just stop working than blow my GB.
Any help would be great, want to resolve this problem asap, I have grown to attached to my mx5 to see it like this haha. It’s a 1.6 na 1990 5 speed manual. I also checked the fluid level (little square container and large round container) and they look full?

leak.jpg

koop21 · Postby **koop21** » Mon Mar 04, 2013 4:20 pm

For the oil that appears to be leaking from the top your clutch fork boot, you may want to get your CAS O-ring seal. Typical symptoms include oil on the top of you gearbox bell housing.

revhead · Postby **revhead** » Mon Mar 04, 2013 4:57 pm

The o ring was changed at service, put my hand under there and there is only the normal oil seepage, no major oil escaping from there. Had a look under the car again expecting fluid to still be there but its mostly evaporated?? Could it be coolant?
I checked the coolant level (was flushed at service) and it sits between max and low.. I would expect it to be at max after a service?

I started the car from cold and watched the rubber boot, and no leaks but as the car warned up sure enough it began to leak from the rubber boot around the clutch fork. Does coolant flow around the transmission housing? Might only leak when the thermostat opens?

manga_blue · Postby **manga_blue** » Mon Mar 04, 2013 5:02 pm

Probably an engine oil leak. As Koop said the first candidate is the CAS o-ring. Takes 15 minutes to replace that and it's a $1 part. It's far too common for mechanics to stuff up the fitting of these o-rings. A new seal that hasn't seated leaks much, much more than an old one that just been sitting there for years and is getting a bit too old. Suggest you talk to the workshop foreman about their quality of work if it's the o-ring.

Slightly less likely is the rear engine crankshaft oil seal. Takes 3 or 4 hours to replace that, plus usually the clutch as well.

revhead · Postby **revhead** » Mon Mar 04, 2013 5:11 pm

I have gone to these guys for years, they do fantastic work, i think they are the only honest mechanics on the planet haha. As said, i don't think its oil anymore, oil doesn't evaporate which is what has happened under my car. i can see the odd oil drop on the ground that has remained. How can coolant be leaking around the clutch fork?

koop21 · Postby **koop21** » Mon Mar 04, 2013 5:16 pm

No coolant flows anywhere near the transmission. If it really is coolant it's likely to be rear hose that connects at the back of motor. Very difficult to get too. Unlikely in my opinion or you would have bigger issues. Please also note that the oil doesn't sit anywhere high enough for it to constantly leak from the cas, the needs to run before it will leak.

manga_blue · Postby **manga_blue** » Mon Mar 04, 2013 5:27 pm

There's a very small coolant (6mm ID?) hose that runs from the back of he head on the driver's side to the oil filter holder under the inlet manifold, directly above the clutch fork. I've seen a few of these fail - they usually wait until you're 500kms from home before they do. There are also two larger heater hoses back there on the passnger side. Failure of any of these three hoses is much more likely if you've had oil seeping into them from an old CAS o-ring leak.

revhead · Postby **revhead** » Mon Mar 04, 2013 5:34 pm

yeah i can see where my old cas o ring was leaking on some pipes and wiring which is why i had it changed. its just that i cant see it run down the transmission and then onto the clutch fork, looks like it is just coming out of the clutch fork. im hoping its just the coolant line and nothing oil related. i will watch the coolant level to see if it drops any more.

it there a specific name for this pain in the ass hose that runs near the clutch fork??

koop21 · Postby **koop21** » Mon Mar 04, 2013 7:10 pm

manga_blue wrote:There's a very small coolant (6mm ID?) hose that runs from the back of he head on the driver's side to the oil filter holder under the inlet manifold, directly above the clutch fork. I've seen a few of these fail - they usually wait until you're 500kms from home before they do. There are also two larger heater hoses back there on the passnger side. Failure of any of these three hoses is much more likely if you've had oil seeping into them from an old CAS o-ring leak.

You are correct here if his car is a na8, my earlier post was referring to na6 they don't have a oil cooler.

revhead · Postby **revhead** » Mon Mar 04, 2013 7:32 pm

Its a 1.6. What would you suggest it be seeing as its a 1.6

revhead · Postby **revhead** » Mon Mar 04, 2013 7:53 pm

so i caved and called racv. he pressure tested and found the leak. its a tiny little "rubber plug" buried behind the engine hidden from line of sight buy the CAS. this plug just goes no where? looks like a rubber bullet?

does anyone know what this is called? is it simply a "rubber plug"? where do i get one?

koop21 · Postby **koop21** » Mon Mar 04, 2013 8:12 pm

this is what you need.
http://www.mx5parts.co.uk/blanking-p-906.html

Good luck getting to it, hopefully you wont loose to much skin on your hands :lol:

revhead · Postby **revhead** » Mon Mar 04, 2013 8:35 pm

thanks, might go down to the local mazda dealer aka "rip off shop" to see how much i can get it for there. I'l try my best to not donate blood to my car against my will haha, might tape up my knuckles and find the longest pair of needle nose pliers i can get my hands on!

im obviously going to lose some coolant, is it bad to mix coolant types because i dont know what coolant my mechanic used? or should i just top it up with water?

koop21 · Postby **koop21** » Mon Mar 04, 2013 9:48 pm

not sure if mixing coolant is bad but if you need to top up use distilled water, water from the tap has minerals which will eventually corrode your cooling system.

hks_kansei · Postby **hks_kansei** » Tue Mar 05, 2013 2:22 pm

revhead wrote:thanks, might go down to the local mazda dealer aka "rip off shop" to see how much i can get it for there?

Try Enzed hoses, supercheap auto, autobarn, bursons, etc.

It's just a rubber cap, it's not a specialty Mazda part.
Just bring the old one and get them to find one the same size etc.