MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Impending Hydraulic Failure

When I got home from work on Friday I noticed 3 drops of oil on the driveway where I had been crawling forward waiting for the garage door to open. I then found another couple of drops on the painted garage floor. The oil was clear, which I put down to the recent oil change. I did a quick look around the engine and found nothing untoward.

I was just about to take the car out this morning to come to work when the alarm bells rang in my mind. I removed the MC cap to find the reservoir almost empty! Another quick check around showed no leaks from the MC nor the 4-way union. I had my suit on so I could not fully inspect underneath the car, but the black pipe to the slave cylinder looked quite wet and, judging from the oil drops on the driveway, the leak is fairly central, putting the clutch slave cylinder/pipe as prime suspects.

I have never had the slave cylinder apart (bought new at rebuild). Any tips on the process for when I get home tonight most welcome.

Steve



Steve Gyles

A clutch cyl rebuild is quite a straight forward job. A little messy with the main metal clutch line dripping, so get something to block it the moment you undo the connection. As far a the clutch cyl itself, it is new so, my guess would be just to buy a rebuild kit and have at it. To the best of my memory, I think there rea only two rubber parts, the main metal cyl and a round metal o-ring. You will need someone to help you bleed the clutch line when finished. All in all not a terrible difficult job. Estimated time : 1 hour. Good luck Gordon
Gordon Harrison

Thanks Gordon.

All the but a small volume of residual fluid at the bottom of the MC has already gone down on the road with each gear change, so the messy part probably won't happen!

Mrs Eezibleed usually does a grand job of the bleeding. Sounds like supply of the new seals likely to consume most of the time.

Steve
Steve Gyles

hi Steve, reference your comment"waiting for the garge door to open" one has visions of your dear lady wife waiting for your return so she can wait outside in all weathers to make sure you can drive straight in whereby she can then light your pipe and get your slippers for you lol


gordon
g c pugh

Gordon

How did you know?!

I am really mystified now. The MC fluid was down to the bridge between the 2 sides. However, no sign of a leak anywhere in the system, clutch and brakes. After she had closed the garage door I got the wife to pump the clutch and brake pedals! All worked tickety booh with correct amount of clutch movement. I then took over and pumped the clutch about 40 times. Again no sign of a leak. Where oh where has the fluid gone? It was definately full at the end of April. The fluid drops on the garage floor are offset, lining up perfectly with the slave cylinder. Could it be a leak that manifests itself only when the car is hot?

Reluctant to use the car for obvious reasons, but not sure where to start. In the meantime I have topped the MC up and will monitor for drops on clean newspaper.

Steve

Steve Gyles

Steve

I had the same thing last year. The brake line running under the engine to the LH front brake had developed a very small hole where held in place with the tab on the chassis. Worked fine until I started to investigate the small patch of clear fluid on the garage floor. It was vibration induced wear, not corrosioin (I use cupro nickel brake lines)

Suggest having a look there. Best way to check is with the system under pressure, so get the Missus to stand on the pedals with as much as she can muster.
dominic clancy

Thanks Dominic. I will investigate. There is certainly a bit of dampness in that general area and spreading back on the underside of the sump. I was assuming it might be a bit of engine oil. I recently filled with 5-40 synthetic and was thinking it might be seeping through oil seals up front, but you now have me wondering.

Mrs G is going to get worn out with all the pedal pushing!!

Steve

PS. Electric door. She found the manual opening too much so I converted it for her birthday present.
Steve Gyles

Just seen that I now live in Avon (last post). No idea where that came from. I never touched anything!

Steve
Steve Gyles

Hi Steve you are all heart


gordon
g c pugh

Steve,
You might want to look at a self propelled lawnmower for your wife's Christmas present. Also, they do make self propelled vacuum cleaners. My wife loves them, it only takes her half the time to cut the lawn or vacuum the living room.
mike parker

BTW, by increasing your wife's productivity and reducing her workload, don't be surprised if things at home improve. You will be amazed at what the increase in domestic productivity can do to a woman. You will see improvements in the cleanliness of the home, the quality of dinner and her happiness, to name a few things. I am sure that you can see the benefits to this little thoughtfulness on your part.
mike parker

Mike

Only recently got mains electricity in Kirkham. Up and over garage door was first electrical item. Not sure about these new fangled lawn mowers. I currently keep her fit using the scythe. Occasionally when she is exhausted I have to borrow a sheep off the local farmer. Carpets? Oak parquet floors here. All hand polished - it's a down on the knees job for her.

Back to the thread. Will check the pipe out later tonight. Not heard of this problem before that Dominic described. Keeping fingers crossed that this is the cause. Nothing worse than unidentified problems, especially those that keep you off the road.

Steve
Steve Gyles

Well, I have to say I am totally baffled. I have examined every inch of hydraulic line. I have been for a hard 20 mile drive with plenty of deliberate braking and gear changes. If any thing I now have more fluid in the MC than before (expansion through heating I expect). Not a drop of oil anywhere - hydraulics nor engine.

The only bonus was that while I had the battery cover off I found one of the battery cables almost falling out of its terminal post connector. The connector has 2 screws that hold the cable in place. The whole set up had worked loose. That probably accounted for some of my poor starting I have been suffering. The looseness did not show up on previous inspections; I merely checked the connector for tightness to the terminal post, and not the cable for its attachment to the connector!

Steve
(Confused of Kirkham)
Steve Gyles

Steve,
I am sure that your wife appreciates that scythe and the parquet flooring. Most women don't realize how considerate their men are by helping them keep fit and minimizing spa costs at the same time. Glad you found the battery terminal issue.
Thinking about your hydraulics situation- you may wish to check the outside bottom of the master cylinder for signs of fluid. I have seen previously a reservoir that had porosity problems.
mike parker

Mike

I am not discounting the possibility of a very minor seepage from the front plate. I was able to comfortably tighten the 2 retaining screws just under quarter of a turn each and it was very slightly damp round the gasket. However, nothing had dripped onto the brackets or shelf. Would silicone fluid just evaporate in that sort of situation without dripping? Perhaps it could in the hostile environment in the engine compartment?

Other than that I can only assume that silicone fluid is now more valuable than petrol and someone has syphoned it off!!

Steve

PS. Kirkham been on mains power for many decades. We even have indoor toilets up here in North West England, contrary to the belief of many Southerners. We also have the best amateur football (soccer) team in England, having recently won the National Vase Cup at Wembley Stadium.
Steve Gyles

Steve,
Silicone fluid will not evaporate. If you cannot find it outside the system, check whether you can find it inside the system. The MC shares with both brakes and clutch. Have you checked your brake system for leakage?
PS, I had assumed that, but was having fun with it. If you would like a scythe handle, like new, I have one I need to get rid of. Lost the blade somewhere.
mike parker

Steve,
If the slave cylinder is leaking it will be wet with hydraulic fluid inside the boot and be coming out where the push rod fits. The boot can hold quite a bit of fluid inside before it starts to drip out.
(depending how shriveled it is from motor oil blowing on it or heat or age!)
I had a similar problem a few years ago where the fluid level dropped once and had seemed to have "fixed" itself. Of course it hadn't and the source was the 48 year old slave cylinder that I had "rebiult" during the restoration of the car about 4 years earlier. I replaced it with a new one :>)

Ralph
Ralph

Steve

Before you home in too firmly on the master cylinder, would this have caused the drip pattern you saw on the garage floor.

If you find nothing wrong and want piece of mind it might be an idea to fit a low fluid warning device, I am sure I have seen details of something fitted into the master cylinder lid.
Malcolm Asquith

Ralph

I will have a look at the boot this evening. The drips occurred while I was creeping forward on the clutch so it is a possibility that the resulting prolongued pressure on the boot allowed it to drip. Outwardly it looks in very good condition.

Malcolm

The dripping on the ground in no way came from the MC. If Ralph's theory comes to nothing I am not sure what else I can do. Since those half a dozen drops of oil the car has been absolutely dry - I bet there are many other owners who would like to be able to say that. I my case I wish it would put some oil down on the ground and give me a clue!

Steve
Steve Gyles

Boot is dry as a bone.

Seems to be a small weapage still from the MC front plate which I will monitor but absolutely no obvious sign of fluid migration from the MC outercasing to elsewhere. If this is the source of the leak, the fluid is either evapourating or it is being soaked up by the braided cotton covered cable loom. I am beginning to think that the one-off oil drops on the drive are a red herring in this hydraulic leak quest.

Steve
Steve Gyles

Steve:

A diagnostic suggestion...First park the car in a clean area or put some fresh cardboard under the area of interest (e.g., beneath the clutch slave cylinder). Then use a block of wood or some other means to hold the pedal to the floor. (Alternatively, you can loosen the jam nut on the master cylinder-actuating rod and screw the rod out from the clevis until the clutch line is under hydrolytic pressure. Leave the car overnight and see if fluid accumulates on the clean surface. If it does, you should have a good idea where the leak is. If you use the adjusting rod method, be sure to readjust the rod for the specified play after the diagnosis.

(This is also a good method of determining how tight the master cylinder and lines are. If the system holds pressure for several hours, they are good to go.)


Steve
Steve Brandt

Regarding the Master cylinder fluid level warning, I have one that I purchased off of Ebay a couple of years ago, but have been otherwise occupied on building my garage to give details. I will pull it out of the box and post details on it today.
mike parker

Steve,
Well, its good that the slave cylinder is not leaking, but the fluid went somewhere, I can't see it evaporating.
You have a point, maybe the oil drips are not connected with the fluid loss. Could a wheel cylinder be leaking and getting inside one of the brake drums or on the inside of a road wheel if you have disc brakes? How about the brake hose at the rear axle? If it is a hose or brake line/ fitting it would continue to leak. A cylinder seal can sometimes leak intermittently before it is ready to leak steadily. If it were my car I would jack it up and pop the wheels and brake drums to make sure there are no leaks at the cylinders/ calipers etc. and visually check all the hydraulic lines and hoses on the car, and clean the exterior of them at the same time. If I saw nothing I would drive it, at first in a low traffic situation if possible, and check the fluid very often for a while. With everything clean if there is any further unusual loss of fluid it should be easy to find the source. Good Luck

Ralph
Ralph

You chaps may find this quiz helpful

BTW: If you do rebuild the slave have the Mrs. hone it before she installs the new seal.

Rich




Rich McKIe

"Occasionally when she is exhausted I have to borrow a sheep off the local farmer."

I'm not sure that I would personnally admit to that in public!
D Balkwill

DB

No secrets on this forum. Elsewhere T McCarthy has problems with noises from the rear end! Lol

Steve
Steve Gyles

Another evening of fruitless searching. All the wheels off and rear drums. Everywhere absolutely clean and dry. Only interesting was the attached oil stain on the underseal of the right hand inner wing. Assumed it was the damper, but that too was pretty dry on the outside. I guess it took about about 15ml of fluid. And no, I have little reason to believe it's the missing silicon fluid.

Steve


Steve Gyles

I'm sorry, but I am running into serious digital camera problems. I will post the pictures on another thread as soon as I sort this.
mike parker

This thread was discussed between 09/06/2008 and 15/06/2008

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.