Dual 7" Servo - Page 17

Mike · #**321** 13th January 2012, 07:51

Dear confused

The dual servo is a sealed unit, and has a closed recess of only 25mm deep.

Mike

Quote:

Originally Posted by MartinClan

I'm confused.

If the metro servo works with the BMW master cylinder then why not the Dual Servo? The plunger arrangment in the Metro servo looked quite similar to that of the dual servo when I looked at my spare metro servo last night.

As I remember the operating rod on the master cylinder is hollow and the plunger from the servo goes up the middle.

Cheers

Robin

Edit:
OK - I looked at the picture of the cutway servo. I can see the problem now. The dual servo has a seat that the metro servo didn't have. The metro servo relying on the tip of the push rod instead.

Mike · #**322** 13th January 2012, 08:11

Guys

Please be careful.

The brake master cylinder has to be one of the most significant safety critical items on any car. Embarking on a procedure to cut and carve must be undertaken with great care.
Suitable new master cylinders are available for £30-40: is it really worth the effort, and risk?
Mike

Quote:

Originally Posted by MartinClan

Before we all go and buy new master cylinders wouldn't it be worth:

1. Working out how much the push rod can move when the brake pedal is flat on the floor.

2. If, in this position there would still some operating rod visible on the master cylinder, then it would be safe to shorten it.

However I guess that shortening it may not be that easy. From its color I guess that the operating rod is made of a high carbon steel. Will probably need a cutting disc in an angle grinder.

Robin

GreatOldOne · #**323** 13th January 2012, 08:22

Quote:

Originally Posted by GreatOldOne

No sign of mine yet.

Maybe the postie has tried today?

Yes, he did. I'll pick it up today from the post office, as apparently it takes Pat 24 hours to get back to the depot...

Mike · #**324** 13th January 2012, 08:27

V8 Peter

I hope the comment from David Siddall below helps.
GOO did the same on the prototype. A longer high tensile M6 would achieve the same more easily. Better still if you then add extra spacer/lock nuts to create a stiffer section over the exposed threaded length.

Mike

Quote:

Originally Posted by Mike

Hi All

David Siddall collected one of the two sample servos on Saturday, and has just sent me the following comments:

[Hi Mike. Just a note to say that I've installed the servo and although I've only been up and down the drive, first impressions are very favourable. The brake pedal has more bite which is what I wanted.
The adjustment on the servo pushrod is not quite long enough with the m/c that I have, so I turned a suitable radius on a 25 mm length of 10mm diameter rod and put m6 thread into it which screws into the end of the servo pushrod.* This brought the end of the pushrod just flush with m/c face of the adaptor plate which is where the metro pushrod was.
I'm happy with the adaptor plate that you've already sent**: studs welded in and a coat of hammerite and it looks fine.
I hope you are as pleased when you get to fit yours...................thanks once again. Regards David. ]

* GOO has prepared exactly the same for his Sportster as par6t of his evening classes ( - and very kindly one for me too.)
** I gave David one of the first prototype adaptor plates designed for the Duksville servo, so the vacuum elbow was slightly out of place.

I have asked David to give us a more extensive report when he has had the chance to go out on the road and test it more fully.

But re-inforces GOO's comments...............................

GreatOldOne · #**325** 13th January 2012, 11:23

If anyone is interested, I'll draw up some plans with dimensions etc for the adjustable rod I turned for Mike and myself.

It's not much - just a 6mm threaded rod that increases in diameter at the end to 10mm, as per the adapter that Robin drew up

http://www.msportster.co.uk/?questio...ks-12-way-down

morris · #**326** 13th January 2012, 11:29

this was my background thought. Taking 10mm off the end would be straight forward and low risk but I think that 25mm will see the push rod go well past the outer edge of the M/C. If we could get some extra adapters made up you could layer up another 2 and then it's just a 15mm cut. it will start to look a bit rubbish though.

The only problem I can see with moving over to a Ford M/C (apart from the fact we're not sure which one to go for) is that although new cylinders are available on ebay, I've not found a single reservior. This is fine for those with remotes but no good if you want to go the traditional route. I think if we can nail down the correct Ford M/C then as you say, it's more than worth the extra £40 to do the job properly.

Quote:

Originally Posted by Mike

Guys

Please be careful.

The brake master cylinder has to be one of the most significant safety critical items on any car. Embarking on a procedure to cut and carve must be undertaken with great care.
Suitable new master cylinders are available for £30-40: is it really worth the effort, and risk?
Mike

MartinClan · #**327** 13th January 2012, 12:45

Perhaps someone has an old BMW master cylinder that can be stripped to see what's what?

If we can't do that then I agree a new master cylinder of an alternative design is the best bet.

Jason - does your master cylinder have any ID on it at all that might give a clue as to its origin?

Robin

Mike · #**328** 13th January 2012, 13:27

Ian

Reservoirs are available in scrapyards on old Sierras, and more modern Fords. I'm told Sierras are scarce down South, but readily available in t' North.

Mike

Quote:

Originally Posted by morris

The only problem I can see with moving over to a Ford M/C (apart from the fact we're not sure which one to go for) is that although new cylinders are available on ebay, I've not found a single reservior. This is fine for those with remotes but no good if you want to go the traditional route. I think if we can nail down the correct Ford M/C then as you say, it's more than worth the extra £40 to do the job properly.

cabrioman · #**329** 13th January 2012, 13:46

Quote:

Originally Posted by MIKE

Simon Gregory fitted one from an XR4i and said it is good. Peter Morris fitted one from a 1.8 LX Sierra one and said it was good too! The smaller the diameter, the better the brake pressure will be: the down side being more pedal travel for the same effect.

The situation with the Ford master cylinder is even worse than you imply. There are also two very different flange sizes and hole centres! I beleive the better one to get is Lucas Girling, and not the Bendix one. The adaptor plate has been supplied with an etched 70mm pcd for the smaller flanged BMC, with holes at 70mm centres (Lucas Girling? - please check first though).
I have seen ones like I chose advertised for Transit Vans. John Tootle (Cabrioman) was going to investigate this - don't know how far he got.

As Mike has said I decided to swap my Hunter M/Cyl with remote reservoir back to a standard Sierra M/Cyl with the reservoir mounted on the cylinder as per Mikes. Fortunatly I had one in the garage as a spare from my original Cabrio donor Sierra, a 1992 Sierra 2.0 LX. The only marks on the cylinder are a stamp stating "22" which I understand is the bore size in mm. This is the same cylinder Pete Morris had fitted to his car, again taken from a standard Sierra.

I would think an enquiry at a local motor factors would turn up the correct cylinder (I am prety certain mine is a girling), the difficuly maybe the reservoir. That said although I have not tried it the cylinder I have with the directly mounted reservoir looks like it would take the pipe outlets Marlin used for the remote setup, so that may be a possibility.

John

Mike

I have sent you a PM regards my servo kit.

John

mashtun · #**330** 13th January 2012, 14:12

Quote:

Originally Posted by MartinClan

Perhaps someone has an old BMW master cylinder that can be stripped to see what's what?

I'm stripping a 1994 E36 at the moment and I've got no need for the master cylinder - I'm happy to take it to pieces and take measurements/photos if it'll help someone...

Mark.

MartinClan · #**331** 13th January 2012, 14:29

I found some better pictures of the E30 M/C. It looks that it cannot be used as there is a seal in the bit that protrudes forward of the mounting flange. Shortening the push rod 25mm would almost certainly compromise this as the push rod would disapear past the seal if there was any more than a few mm movement.

Is there a good picture of the M/C used by Jason anywhere that shows this detail for the ?Ford? M/C. Just for comparison....

Robin

morris · #**332** 13th January 2012, 16:09

Robin, then it's as I feared the E30 can't even be fiddled with. Can you point us to the photos you were referring to that show the seal?

Mashtun, thanks for the offer but I think you'll find your E36 M/C is even worse than the E30 one in this instance

The shank that protrudes past the fixing base points is even longer and slightly bigger diameter. I did get mine out of the "to be ebay'ed" box last night for a look but immediately threw it back in when I remembered the reason I had to buy the E30 one in the first place.

So, it's looking like an as yet unidentified ford part or a set of stand off spacers which are almost guaranteed to raise eyebrows at IVA time. I'm going to get the servo mounted up on the pedal box first so then I have an idea of how much there is to play with before the M/C hits the side of the engine compartment

Mike · #**333** 13th January 2012, 16:11

Robin

Does this help? It is a Ford m/c marked "22" - it has markings on it 311809, and Q29

The projection of the Ford m/c beyond its flange face is around 23mm, much the same as the depth of the dual servo recess. The adaptor thickness of 6mm giving sufficient clearance.

Mike

Quote:

Originally Posted by MartinClan

I found some better pictures of the E30 M/C. It looks that it cannot be used as there is a seal in the bit that protrudes forward of the mounting flange. Shortening the push rod 25mm would almost certainly compromise this as the push rod would disapear past the seal if there was any more than a few mm movement.

Is there a good picture of the M/C used by Jason anywhere that shows this detail for the ?Ford? M/C. Just for comparison....

Robin

Mike · #**334** 13th January 2012, 16:16

Ian

In the Cabrio it gets closer to the underside of the bonnet than the side, so be sure to check for height clearance. Of course you may have more room in the Sporster, and it may not be such an issue.
The Ford m/c I have seems quite long. Not sure about Jason's m/c though, although we know it fitted under the bonnet ok.
Mike

Quote:

Originally Posted by morris

I'm going to get the servo mounted up on the pedal box first so then I have an idea of how much there is to play with before the M/C hits the side of the engine compartment

MartinClan · #**335** 13th January 2012, 16:22

Quote:

Originally Posted by morris

Robin, then it's as I feared the E30 can't even be fiddled with. Can you point us to the photos you were referring to that show the seal?

They were just some images on google that I found....

I looked at Jason's web site. I am unable to use the master cylinder similar to he used as it has THREE outputs. The E30 one has two outputs and all my plumbing is likewise. Hmm nothing is ever as simple as it seems. But then it wouldn't be so much fun :-)

Robin

morris · #**336** 13th January 2012, 17:16

Robin, my E30 M/C has 3 outlets as I removed the screw in cap on the bottom though I don't know that this helps you.

Unfortunately I don't have any bodywork yet so all I can do is eyeball it. I've fettled the pedal box now with a round file and trial fitted the servo so at least I've got a reference point to work from. Maybe a tiny power bulge in the bonnet (for the brake reservoir) will be the solution

I've just checked and my E30 M/C cost the princely sum of £12 so despite spending time cleaning it up and making it look all silver and pretty, it qualifies a potential guinea pig for the angle grinder

Stuart · #**337** 13th January 2012, 18:00

So am I right in saying we now need to source a new master cylinder as the BMW one will not fit the new servo?

What diameter is the original BMW unit and what diameter ford unit are we looking for?

Stuart

Grey V8 Pete · #**338** 13th January 2012, 18:11

Hi Mike.
Thanks, I will probably go this route as it seems stronger than extending the push rod screw out too far. Many thanks also for the tip about the G-Cramp.

I ordered some 8mm Hi Tensile Steel countersink screws from Namrick in Hove and they arrived next post so can recommend them as a supplier if anyone else needs them for hooking up the adaptor to the master cylinder. Tel 01273779864 or www.namrick.co.uk
Peter.

Quote:

Originally Posted by Mike

V8 Peter

I hope the comment from David Siddall below helps.
GOO did the same on the prototype. A longer high tensile M6 would achieve the same more easily. Better still if you then add extra spacer/lock nuts to create a stiffer section over the exposed threaded length.

Mike

morris · #**339** 13th January 2012, 18:36

I have...a cunning plan

This looks very dodgy but is actually pretty strong. With some reinforcement on the front face of the servo and standoff sleeves at 4 x opposite points it could work nicely. The stand off gains 15mm so the M/C would only need 10mm trimming from the end of the plunger. I'll be spinning the Servo 90 degrees anticlockwise so I can mount the M/S the right way up and keep my reservoir

This all of course depends 100% on the assertion that the M/C and servo don't need an air tight seal because in this case, I think I'd struggle to make one

As far as I can tell this also will not cause the M/C to foul either the side panels or the bonnet (thought the latter is guess work). If one of the other builders can mock up the same thing and make a few measurements this may be some way to the solution

jeremy · #**340** 13th January 2012, 18:56

From memory I am using a ford m.c. -think it is this as it is mounted at an angle with remote reservoir on metro servo. looking at it in-situ it has the number 383059 on it