MKI / MKII S type 240 340 & Daimler 1955 - 1967

how to disable power brake servo on 67 mk2

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  #21  
Old 06-20-2024, 12:29 AM
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I would just like to reinforce Peter's advice and say don't do it.
Just think of the brake master cylinder as a controller of the more powerful brake servo
I have had to move Mk1s and MK2s with unserviceable brake servos around between sheds on my acreage property.
Even the early drum brake MK1s will not pull up easily.
With the disc brake cars i.e. late model MK1s and the MK2s you simply cannot get anywhere near enough pressure on the pads to brake safely.
There is no way I would even consider going on a public road with no brake servo.

 
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  #22  
Old 06-20-2024, 06:13 AM
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With the caveat that it has been quite some time since I did business with them, Whitepost Restorations used to be our "go to" source for brake component rebuilding, including servos.

Brake Sleeving & Rebuilding Services – White Post Restorations

I have driven a MK-2 sans servo for a short distance and I can guarantee that you would not like the experience.
 
  #23  
Old 06-20-2024, 07:33 AM
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thanks to all for their concerns WRT my safety and that of the public in general. i assure you that if and when i disabled a power braking system on a vehicle i would take the time and trouble to verify that it could then be driven with the same safety margins that i, and the public, had previously enjoyed.

maybe i should explain....

knowing that the private storage facility where the car is kept opens at 9:00 a.m. and closes at 5:00 p.m. and that i only have, at best, once travel time as been accounted for, about six hours to complete a maintenance task, and if not completed the car will have to be left in a public parking lot frequented at all times of the day and night by idle neighborhood teenagers, smoking dope and drinking beer, i must have a backup plan to answer the question "what if i don't finish this task in time?". .

the "run it without power brakes if necessary so i can get it back to the storage facility" is the backup plan. and this thread was created in an attempt to take the first step to verify that the plan was feasible. and to do that i wanted and may still want to create a MK2 designed with power brakes that HAS no power brakes, specifically to test whether or not such a MK2 was safe to drive. as driving the car back to the storage facility after failing to either fix or install a new or rebuilt servo may be necessary.

IOW, safety, in a round about way, was the driving factor in the creation of this thread. but prefacing it, if only to allay safety fears in an introductory post, with such a convoluted and lengthy preamble, was never seriously considered. maybe it should have been..

again, thanks to all for their concern.
 

Last edited by hueyhoolihan; 06-20-2024 at 07:40 AM.
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  #24  
Old 06-20-2024, 07:45 PM
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I can second S-Type Owners nod to White Post Restorations. They rebuilt my original servo with all the correct plating, hardware, etc. They also bored, sleeved and rebuilt my caliper piston assemblies and my master cylinder. The nice thing about putting the originals back in the car is that they fit without modification.
 
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  #25  
Old 06-21-2024, 12:54 AM
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Yes ~ I stainless steel lined all hydraulic components.
 
  #26  
Old 06-22-2024, 04:18 PM
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i managed to remove the white plastic vacuum release mechanism on the remote servo today. thanks to all who contributed info WRT the project!!! it's shaped like a round 4-5" car speaker. this disabled the power brakes. i was not surprised.

one circumnavigation of the parking lot and it was cleat that more pressure on the pedal was needed to stop the car, but not to the point that it couldn't be driven safely. maybe not with pleasure, but safely, at least on the dry suburban roads on a summer's day in california. and safely enough to get the car back to the storage area and if necessary to my shop (ten miles) if necessary, but as it turned out it may not be necessary.

the "speaker", in addition to the disk and rubber gasket, has a number of white nylon pieces running along its central axis. from three or four plastic pieces to two or three black rubber grommets and one piece that looks a lot like a blunt carb needle, but it looks like it (the needle) has broken off of its support piece where they join. now i'm wondering if somethign wasn't so much stuck as broken...hmmm.

and try as i might, applying the brakes after removal didn't product a piston from inside the servo. just the plastic and rubber pieces that were removed. anyway...

i've decided to buy a new remote servo and will probably have my mech install it as there is little chance i could get it installed in a day. even if i could buy just the release mechanism, i'm not sure that that is all that's wrong with the servo.

surprisingly, when i put everything back together (and without too much care BTW) the power brakes worked again, albeit no better than they had before.

i'm looking at the SNG U.S A. website and their LR18230 remote servo as a replacement servo. anyone with cause to object?

https://www.britishautousa.com/produ...51c4efdaf3409e
 

Last edited by hueyhoolihan; 06-22-2024 at 04:27 PM.
  #27  
Old 06-22-2024, 05:53 PM
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It's not as difficult to remove and replace the servo as it might appear. When my brakes were sticking, I took it out, opened it, and put it back three or four times over a day and a half (before I realised the air/vac piston was sticking). The only complication may be if you need to re-arrange the mounting or connections for the replacement.
 
  #28  
Old 06-22-2024, 06:01 PM
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Originally Posted by Peter3442
It's not as difficult to remove and replace the servo as it might appear. When my brakes were sticking, I took it out, opened it, and put it back three or four times over a day and a half (before I realised the air/vac piston was sticking). The only complication may be if you need to re-arrange the mounting or connections for the replacement.
maybe i'll take another look at it. after all, now that i know i can drive the car and get it back to the storage facility if i can't accomplish the installation in one day, i suppose it's not all that important if i do or don't.
 
  #29  
Old 06-23-2024, 02:20 AM
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Originally Posted by hueyhoolihan
i managed to remove the white plastic vacuum release mechanism on the remote servo today. thanks to all who contributed info WRT the project!!! it's shaped like a round 4-5" car speaker. this disabled the power brakes. i was not surprised.

one circumnavigation of the parking lot and it was cleat that more pressure on the pedal was needed to stop the car, but not to the point that it couldn't be driven safely. maybe not with pleasure, but safely, at least on the dry suburban roads on a summer's day in california. and safely enough to get the car back to the storage area and if necessary to my shop (ten miles) if necessary, but as it turned out it may not be necessary.

the "speaker", in addition to the disk and rubber gasket, has a number of white nylon pieces running along its central axis. from three or four plastic pieces to two or three black rubber grommets and one piece that looks a lot like a blunt carb needle, but it looks like it (the needle) has broken off of its support piece where they join. now i'm wondering if somethign wasn't so much stuck as broken...hmmm.

and try as i might, applying the brakes after removal didn't product a piston from inside the servo. just the plastic and rubber pieces that were removed. anyway...

i've decided to buy a new remote servo and will probably have my mech install it as there is little chance i could get it installed in a day. even if i could buy just the release mechanism, i'm not sure that that is all that's wrong with the servo.

surprisingly, when i put everything back together (and without too much care BTW) the power brakes worked again, albeit no better than they had before.

i'm looking at the SNG U.S A. website and their LR18230 remote servo as a replacement servo. anyone with cause to object?

https://www.britishautousa.com/produ...51c4efdaf3409e
No problem at all Huey.
 
The following 2 users liked this post by Glyn M Ruck:
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