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hugo #803960 20/07/24 02:10 PM
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S
Has a lot to Say!
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Just a thought, Brake fluid is quite hygroscopic and like you see rust appearing within your wheel cylinders and damaging them so to do you in clutch slave cylinders. Perhaps they had applied the coating to the piston shaft to prevent this as rust suspended in the fluid would promote wear quickly, Not sure the the coating was that well tested though innocent

hugo #803964 20/07/24 03:19 PM
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Talk Morgan Regular
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Originally Posted by hugo
... there was bits of plastic trapped on the seals and were badly scored, the oil was also very dark

"MBH" stands for Morgan Brake Hydraulics. MMC numbers are not much help in finding the generic part you need or the general lore you need.

Hugo, clutch MCs have a normal lifetime, assuming the right fluid (always flushed to be clear as crystal clean water), the ambient humidity and proper angling of the rod, of
70,000 to 110,000 miles. The last should be a given but Morgans can be unusual). With that, they merely need to have their seals changed. 10-15 pounds. The fluid used should
be DOT3, DOT4, or DOT5.1, which are all compatible. but some owners dangerously change it to DOT5. ooo

It is very common that owners will let their clutch/brake fluid get to the point where it is shot, much less effective and destroys seals, allows internal rust, etc. As well, unbelievably,
many dealers do not have it on their service list. LASTLY, The same fluids are used in the brake system and that system, an even more vital and elaborate one, will react to the bad
fluid in an unfortunate fashion. The brake system has a master cylinder also along with two calipers (front) and two wheel cylinders and the lines between them. My guess is that
you will find the brake system's fluid has gone very bad as well. frown2

I am very impressed that you removed your MC and its push rod. That took more skill than anything else one needs to do to keep these systems in top shape, though you have
reason to be concerned about its internals if the fluid is in the same condition. Considering that pleasant bravado, I would normally have suggested you look to Sewin's solution of
merely changing the seals if it were not for the push rod coating. Of course, the world using that part will have upgraded forever push rods but you would need the manufacturer part#.
I believe I see upgraded rods for 34$ on ebay.

May I suggest you buy a hydraulic fluid tester? However, just looking at the fluid color regularly (once a year) is ok.
If it has begun to go even a very pale light golden, change it.

Do you know how to change hydraulic fluid? You need an extra leg to pump the pedals, so having a life partner is important to Morgan ownership. laugh I call them , in my case SWAUW
(aka SHE WHO ADDS TO SPRUNG WEIGHT).

The rest is easy. Save you a couple of 100 and you can choose your fluid type Many here can guide you. I like DOT 5.1. or it is detailed on gomog. Good luck

gmg

P.S. The only serious watchpoint is the fluid itself. It is hygroscopic. If it gets on you, and is not quickly removed, it will remove skin. Smarter people than me use plastic gloves. (wryly)

Last edited by gomog; 20/07/24 03:22 PM.
gomog #803966 20/07/24 03:41 PM
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Talk Morgan Regular
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Hugo?

Is this a match? However it is not upgraded. merely the same parts that came with the car and supplied through the Morgan network. But with normal care, it will suffice for another 70k unless the cylinder has rusted.

If you took the old one out, you can put the new one back in.

Last edited by gomog; 20/07/24 03:48 PM.
hugo #803976 20/07/24 08:07 PM
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Just barreling along
Needs to Get Out More!
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Just barreling along
Needs to Get Out More!
Joined: Nov 2015
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Likes: 501
Originally Posted by hugo
[Linked Image]

This is the master cylinder internals, the shaft has a plastic coating that has started to peel , there was bits of plastic trapped on the seals and were badly scored, the oil was also very dark


Hugo, I wouldn't waste time with the official dealers as they are tied under contract to buy spares in from MMC & then re-sell to end users

Jump the queue and save a few ££ and try Cain at Wolf Performance, great knowledge and generally has stock of common stuff that fails (like brake & clutch hydraulics)
https://www.wolfperformance.co.uk/


Jon M
hugo #803981 20/07/24 10:20 PM
Joined: Jul 2019
Posts: 104
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L - Learner Plates On
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Morgan Plus4 2019 (trad) with Mazda Box:
11000km failed master cylinder and replaced under Morgan warranty.
33000km. Found a drop of clutch fluid under the reservoir. Checked the fluid and found magnetic particles. See pic. Clutch was still working though. But pressure was too high so clutch fluid came out from the cap of the reservoir.
Investigated master and slave cylinder. Slave cylinder full of particles. This time I changed both cylinders. Maybe I should have done before, since the whole system was affected.
The part numbers of what I got now: See pics.
[Linked Image]clutch reservoir by Werni Wehrli, auf Flickr
[Linked Image]1000012500 by Werni Wehrli, auf Flickr
[Linked Image]1000012499 by Werni Wehrli, auf Flickr


Plus 4 110 Edition 2019
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