Marina rear brake bleed problem...

[element]

Re: Marina rear brake bleed problem...

Absolutely!

[element]

Re: Marina rear brake bleed problem...

Ok, I put in the new flexy pipe & began bleeding again. Initially air came through & a very small amount of fluid then it just stopped altogether... Figured something was wrong so I undid the lower flexy union and pedal pressed & sure enough fluid did show. Tried again but still the same.. It was at this point I noticed some drips on the floor beneath the master cylinder area On checking it I find that the surface where the master cylinder bolts on to the servo was wet and rubbing with a finger it was corroded with some rust and doesn't look good. I'll try to get a photo up later on... The actual master cylinder looks dry & ok but it is the forward face of the servo that is wet with fluid. I imagine there's some kind of seal in there that has gone?

[stevejgreen]

Re: Marina rear brake bleed problem...

Ok, I put in the new flexy pipe & began bleeding again. Initially air came through & a very small amount of fluid then it just stopped altogether... Figured something was wrong so I undid the lower flexy union and pedal pressed & sure enough fluid did show. Tried again but still the same.. It was at this point I noticed some drips on the floor beneath the master cylinder area On checking it I find that the surface where the master cylinder bolts on to the servo was wet and rubbing with a finger it was corroded with some rust and doesn't look good. I'll try to get a photo up later on... The actual master cylinder looks dry & ok but it is the forward face of the servo that is wet with fluid. I imagine there's some kind of seal in there that has gone?

Yep, popped the master cylinder push rod seal. Time for a refurbished master cylinder I think.

This might help here or there

[element]

Re: Marina rear brake bleed problem...

Some pics...







This is (as far as I know) a dual circuit master cylinder but in order to identify exactly which one - I have to remove it to read the serial stamp mark - is that right? Then hopefully I can just order a seal kit from Rimmer Bros - or somewhere else rather than get a new / refurbished one.. at least this is my plan. Kind of hoping the servo will just be surface paint (due to the fluid) deterioration & rust which can be cleaned up and repainted...

[stevejgreen]

Re: Marina rear brake bleed problem...

To my knowledge there is no Triumph direct replacement for a Marina/Ital master cylinder.
There are other alternatives but they involve more work than a simple swap.
I suggest you talk to Chris Weedon, he has done a lot of work in the past and continues to research possibilities for the Morris Marina Owners Club even if your dual master cylinder is not specifically listed.

[b_caswell]

Re: Marina rear brake bleed problem...

Trying to cross match common parts is very difficult as they all use different part numbers.

However some Dolomites uses an option with a similar direct servo and tandem master cylinder to the Marina. There are at least three cylinder service packs covering the 1300/1500 then 1850 and Sprint.

The only info I can find is that the 1300/1500 Dolly with the tandem system has a cylinder bore of 0.75".

Not sure what the Marina bore is but first thing to do would be to strip it and have a measure of the bore. Also careful examination of the seals under a magnifying glass may reveal a seal number that may be useful.

[stevejgreen]

Re: Marina rear brake bleed problem...

I have dug out some old research on a post it note on the back cover of a parts book.
The original and as far as I am aware only Dual Master Cylinder was

37H8701
which was superceded by
GMC 148
which in turn was superceded by
GMC 176

I do not have details on any of these, only part numbers. Whether seal kits are the same or not, who knows.

Typing Marina parts numbers into Rimmer Bros search box usually turns up results, if they were common parts on a Triumph.

If this fails, I repeat my suggestion earlier, talk to Chris, he has replacements for the single circuit cylinders, etc. and I understand he was working on the dual in line variant.

[element]

Re: Marina rear brake bleed problem...

Thanks for the hard effort and research - humble pie time... In my naivety I had thought it was a duel circuit type master cylinder because there were 2 pipes exiting it... However in conversation with a mechanic recently - he told me that 'actually' it is most unlikely to be a duel circuit & that the single & duel don't mean one or two pipes leaving the cylinder... So tomorrow I'll remove it and look for the serial number which I'm led to believe is often stamped on it underneath. Maybe tomorrow will bring some closure to the problem... This is the last thing in the way of the MOT.. so hopefully not long now as Summer's arrived up here the the highland roads are calling for a series of long roaring drives

[b_caswell]

Re: Marina rear brake bleed problem...

Would be interested to see a picture that shows the whole master cylinder. If it has two brake lines exiting the bore casting its a tandem system one line to the front and the other to the rear.

[philcoyle]

Re: Marina rear brake bleed problem...

If it has one pipe diameter larger than the other, one is unf the other is metric it has every chance that it is a tandem master cylinder.

[stevejgreen]

Re: Marina rear brake bleed problem...

Do you know what your on or car was? It was only the later models that were fitted with dual/tandem brakes.
All the master cylinder variants for single circuit brakes had drum shaped reservoirs, only the dual circuit brakes has a rectangular reservoir, sloped at the bottom to give two inlets to the master cylinder, and it's two outlets! That alone, given what can be seen in your pictures so far suggest a dual/tandem master cylinder.

Now I have to use my memory. The filler cap was fitted centrally to the master cylinder reservoir, I do not recall that any of the standard Marina/Ital dual/tandem master cylinders were ever fitted with a brake fluid level switch, as in your picture. A quick scan of the wiring diagrams seems to confirm this though there are brake warning lights connected to a non adjustable differential pressure switch.
But of course what you actually have, may be from another vehicle entirely, for instance there are some LandRover dual/tandem master cylinders that will fit,
I doubt that by removing the Master Cylinder will reveal any part numbers. Often identical castings were machined to different dimensions, even as simple as changing from imperial to metric threads. But I would not rule out the possibility.

Something I raised earlier and your experience has conformed it. Somewhere in your system is a significant source of the blockage, and it appears to be moving. A thorough flush might dislodge it, but could you ever be certain? I would certainly be thinking about replacing all the pipework and critically inspecting any associated hydraulic devices. The nearer the source of the debris is to the master cylinder, the greater the chance it has infected every part of the brake system.

And finally, have you contacted Chris Weedon yet? When he fitted Ford Disks and Princess Calipers, he did a fair amount of research. Equally he has investigated and sourced all Marina/Ital clutch master and slave, single circuit brake systems and is expanding into Dual Circuit. Some of this is detailed on his own personal website and is well worth reading.

[element]

Re: Marina rear brake bleed problem...

Ok, I haven't contacted Chris Weedon yet - only in the last hour have I got the MC off the car & got the serial number & some photos... I have no idea what the original car was that this part came from - my Dad built it 15+ yrs ago & all he can remember is that he believes it came from a Marina; which model, age, reg, type engine size - we have nothing on these.

The pics:











I have a basic working knowledge of how the brakes work - but there is clearly brake fluid inside the inner bowl of the servo & I'm not sure that's right? The M/C is held onto the servo by two 17mm nuts on threaded studs either side of the M/C.

The rear brake pipe union to the M/C was 11mm & the front one was 13mm!

I think the serial number (the wonders of a bit of sandpaper) is GIRLING 646789120104 and the closest match I can find to that is here:
http://www.earlpart.co.uk/catalogue%20marina.pdf - top of pg 5, second paragraph - it lists Body No 64678912

I think my best bet is to send it it to someone that refurbishes such parts rather than chance it with a 'repair kit'.. Can you recommend anyone - would Chris Weedon be the man to talk to now that I have this info?

Other matters - the blockage was the collapse of the inner core of the flexy brake pipe at the rear; once removed & pedal pressed - a good squirt came through. Put the new flexy on and fluid did come through it. After the flexy the first copper brake pipe goes to the rear offside cylinder. Then a second one leaves the same cylinder & goes to the rear nearside brake cylinder, where there is a bleed valve. On trying to bleed the rear pipework after fitting the new flexy pipe it went all stop with nothing coming through, not even air, after a while. It was at this moment that I found the M/C was leaking fluid from the seal between it and the servo.
If, after replacing the renewed M/C I still find nothing coming through to the rear valve then I have an air compressor & may be able to blow some air through the various pipes etc to try to remove any possible blockage. However until the M/C is replaced I won't know whether I need to do this or not...

I have a couple of pics taken of the servo without the M/C but can't access them until tomorrow now.

I know it would make things easier if I also measured the bore of the M/C - have to do that tomorrow...

[stevejgreen]

Re: Marina rear brake bleed problem...

That certainly looks like a late Marina/Ital dual tandem master cylinder. The hunt for replacement seals can now start.
In my keepandshare archive there are four data sheets in the Girling section that may help further. Something in excess of 35mb of PDF files. I have not examined them for a couple of years.

If the blockage was as a result of a failed flexy, and you have simply pumped it further along the cross pipe between each wheel, then you could be OK. I have to suggest though that a vacuum flush, will hopefully pull any debris out, rather than push and compress any debris into a more distant location. It is also much kinder to master and slave cylinder seals. Certainly a vacuum brake bleeder is much less likely to inadvertently squirt brake fluid over your nice paintwork.

There should be two seal sets, one on the piston of the master cylinder, and one in the mating face of the servo. As the servo is connected to the inlet manifold, which in turn is connected to the engine breather, although the connection to the servo is a non return valve it is not unusual for oily fluids to build up inside the servo, not just hydraulic fluid, over a period of years. It's an assembly that rarely gets taken apart unless there is another problem.

Beware of Earlpart. Often over priced and their stock list is less than accurate.

[element]

Re: Marina rear brake bleed problem...

Ok, thanks for the heads up- I'll start digging

[philcoyle]

Re: Marina rear brake bleed problem...

I recall that I had a similar problem bleeding the brakes on my roadster about 15 years ago, it turned out that the valve that the pipes go to from the master cylinder and then go off to the front and the rear was jammed. What happens is the piston inside the valve slides across blocking the part of the braking system that has lost pressure, this is due to the pressure in the other side forcing the piston across to block off the front or rear brakes when you press the brake pedal, and so you always have one part of the braking system working if the other part fails.

I removed the valve and fitted a T piece into the front brake pipes and fitted a new pipe from the master cylinder to the rear flexi, this still retains a split braking system and has never failed an MOT inspection, I retained the fluid level switch and warning light as I thought it was more prudent. The master cylinder like yours was off a Marina Van, which in later years the servo and m/c was replaced with a Morgan Aero servo and m/c unit, I found all the old parts the other day and this post brought back all those things I had forgotten.