Morris Minor Owners Club

Posted: **Sat Apr 18, 2020 9:20 pm**

Hi,
I was hoping someone can advise me:
I am unable to get a consistently firm brake pedal with the silicone brake fluid I have installed in my renewed braking system, the set up is this:
New brake master cylinder, with rubber 'cap' removed to allow for new Ford vented disc kit at the front (so new calipers).
New wheel cylinders at the rear plus new shoes.
New cunifer brake lines and new flexi-hoses, running through cleaned out and refreshed brass junctions.
The reason I emphsize the 'new' is so you know that none of it has been contaminated with age or previous use with Dot 4 fluid.
I have bled the system through with the 'Gunson Eezibleed' kit using tyre pressure and have silicone fluid at each bleed nipple.
Possibly not enough pressure though??
It will give me a firm(ish), though well depressed, pedal the first time of asking, which locks the front brakes....
But not the rears...
And the second time of asking it doesn't lock the fronts.......
This is with the eezibleed kit removed, with it attached I do get a firmer pedal before I disconnect......
So the question is: what am I doing wrong / not doing??
As an aside the rear brakes are set up correctly and the system does not include a servo or remote reservoir.
Many thanks in advance for any help.
Best wishes,
Mike.

Posted: **Sat Apr 18, 2020 9:27 pm**

Seems, to me that one end of the system is limiting the braking to the other end. A poor man’s “dual circuit” braking system that is not working.

. I very much doubt it has anything to do with the brake fluid.

Posted: **Sat Apr 18, 2020 9:37 pm**

I've run this set up before on others with Dot 4 fluid, without issue.......
Best wishes,
Mike.

Posted: **Sat Apr 18, 2020 9:44 pm**

I use the same method as you, using the ezibleed system, which works ok with silicone, the pressure of the driver tyre is 10- 15 lbs pressure from memory. It might be worth pumping the pedal a couple if times before disconnecting. I’m assuming the reassembly of the master cylinder was correct, after removing the top hot seal, I’m sure it was.
I have heard of the rear cylinders sometimes being difficult to remove air from. Jacking up the rear might be helpful, although I have not had to resort to that before.

Posted: **Sun Apr 19, 2020 10:11 am**

During my restoration of the Van, I too renewed all cylinders/pipes and fitted esm/Marina disc set up and changed to dot5 fluid. Using the easibleed method I had similar pedal. Tried again using "Manual" method and they are now perfect.
I have no idea why this was, because I have successfully used the easibleed kit in the past with no problem?

Posted: **Sun Apr 19, 2020 12:26 pm**

I doubt that it is the fluid. Basically as above suggestions, try jacking rear and manual bleeding with two people.

Posted: **Sun Apr 19, 2020 5:13 pm**

I doubt that it is the fluid. Basically as above suggestions, try jacking rear and manual bleeding with two people.

Tried this without success............
However I found a weep when the system is under tyre pressure, which I may have missed before, between the rear flexi-hose and the brass union. Upon inspection it appears to have chewed the thread, despite my being really careful not to over do tightening things.
However, once removed, I tried it in an old union I have and it was very tight, so I am now wondering if it is the right thread for the Morris unions??.......
To play safe I have ordered a replacement from ESM, if this fits without issue I shall have words with the other company who supplied the flexi-hose I was using, as it was listed for a Morris Minor.
Once it's back together I will have another try at bleeding the system, though if it still doesn't work I shall be sorely tempted to drain the system, blow it through and refill with some Dot 4 I have on the shelf.......
Best wishes,
Mike.

Posted: **Sun Apr 19, 2020 8:29 pm**

After all that I went off for some garden therapy, suitably chilled I now need a beer!
Best wishes,
Mike.

Posted: **Sun Apr 19, 2020 8:35 pm**

: Bremsen layout - Gewinde Verbindungen.jpg (684.14 KiB) Viewed 1631 times

This sktech which was originally here in the Forum from Declan, I think shows where differing BSF -UNF threads are used in the Morris Minor braking system

Posted: **Sun Apr 19, 2020 10:48 pm**

It would be disappointing to refill with dot 4, to find the same difficulty. It can’t be the fluid because many, me included, have successfully bled the Minor system with silicone. Perhaps the issue you have found will help..

Posted: **Mon Apr 20, 2020 6:46 am**

DOT whatever , brake fluid ( hydraulic fluid ) doesn't compress , if there's air in the system , it needs getting rid of..

John ;-)

Posted: **Tue Apr 21, 2020 2:51 pm**

Just waiting for replacement parts from ESM, so I can eliminate the air in the system issue, before I try bleeding the brakes again.
So I thought I'd reassemble my engine in the meantime, only to discover I've misplaced my head nuts......
Not my day, is it........
Best wishes,
Mike.

Posted: **Tue Apr 21, 2020 4:34 pm**

Are they on the studs?

Posted: **Wed Apr 22, 2020 9:43 am**

Are they on the studs?

If only!
Never mind, replacements ordered, along with some other bits. They'll turn up when I'm not looking for them, put somewhere where I wouldn't loose them no doubt!
Best wishes,
Mike.

Posted: **Wed Apr 22, 2020 11:00 am**

I spent ages bleeding the brakes on my minor having fitted a new braking system all round, inc pipes, flexi shoes etc.

I appreciate you have discs fitted, but I found lots of air trapped in the system and had to bleed the system many times before all the air was expelled.

I than wedged the brake pedal down overnight with the rear of the car as high as I could get it, and that did the trick, the rear cylinders are designed with a suitable pocket where the air gathers.

Once I managed to expel the air all was well, oh and that was with Silicone brake fluid.

hope you get sorted.

Posted: **Thu Apr 23, 2020 3:39 pm**

I spent ages bleeding the brakes on my minor having fitted a new braking system all round, inc pipes, flexi shoes etc.

I appreciate you have discs fitted, but I found lots of air trapped in the system and had to bleed the system many times before all the air was expelled.

I than wedged the brake pedal down overnight with the rear of the car as high as I could get it, and that did the trick, the rear cylinders are designed with a suitable pocket where the air gathers.

Once I managed to expel the air all was well, oh and that was with Silicone brake fluid.

Duely noted.
Did you bleed them again in the morning, having left the wedged pedal overnight?

As an aside, I have now received a replacement rear hose and brass union from ESM and guess what??
They fit together a treat, perhaps I should have ordered the hoses from a main supplier in the first place......
Below is a picture of the original (wrong) replacement hose I ordered (top), with the correct ESM one and replacement union below.
You can see the threaded part is too long for the union, yet it was sold as a Morris Minor item....
The threads look the same, yet the one from ESM screws straight in by hand. The other was tight from the outset.
Which, I know, with hindsight should have been a giveaway from the start.
Now though, it's back to the bleeding.......

Many thanks to all and best wishes,
Mike.

: Wrong Goodrich brake hose sent.JPG (1.22 MiB) Viewed 1417 times

Posted: **Thu Apr 23, 2020 4:15 pm**

I trust that you put the copper washer in place between the hose and union?

Posted: **Thu Apr 23, 2020 11:08 pm**

Those threads look different?
I seem to recall when working on my brake fittings they were of a different thread to later installations, BSF/UNF type of problem.

Alan

Posted: **Fri Apr 24, 2020 7:56 am**

jagnut66 wrote: ↑Thu Apr 23, 2020 3:39 pm
Did you bleed them again in the morning, having left the wedged pedal overnight?

Yes I bled them the day after and they worked a treat with a solid pedal.

Posted: **Fri Apr 24, 2020 9:30 am**

Thanks, I know it may have seemed like an obvious question, however I am new to silicone fluid, so thought I would ask.
Best wishes,
Mike.

Morris Minor Owners Club

Problems getting firm brake pedal with silicone fluid

Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid

Re: Problems getting firm brake pedal with silicone fluid