I believe the round shaped diaphragm that creates the vaccum to drive the scuttle vent up and down needs to be replaced. XK's Unlimited said they do not sell that part and so far from web searches I have come up blank?

Does anyone know if there is a replacement part available?

thanks in advance....

 

Have you tried Martin Robey Sales Ltd at Nuneaton in the UK?

Martin Robey

They have the best stock of older Jaguar parts and shipping costs to CA wouldn't be excessive on a small part like that.

Graham

 

Graham,

Thanks for the help. I sent them an e-mail as I could not find it in their catalog for popular parts. I hope it is available as this looks to be one of those either ultra rare or unavailable parts?

 

It could be in the 'no longer available' category by now.

Here's the other major UK suppliers specialising in early Jaguar parts:

David Manners Ltd
Jaguar, Daimler, MG, Mini, Triumph, MX5, Morris Minor, Car Parts from David Manners Group of Companies in the UK

SC Parts
SC Parts

SNG Barratt
SNG Barratt - The Ultimate Jaguar Parts Specialist

TheJagMan
The Jag Man - Classic Jaguar Mk2 and Daimler 250 V8 Spares and Spare Parts for Your Restoration Project

If none of them can supply, you're going to have to get creative and find an alternative!

Graham

 

so far David Manners does not sell that part

Just sent an e-mail to the Jag man and crossing my fingers

 

I just send an e-mail to SC and thus far all others mentioned above do not have this part. It looks like it is an unavailable part?

If anyone knows of some other source for a diaphragm that will work please post it as at some point I am sure others will run into this same issue. I am installing the retroair kit for AC designed for the Jaguar 3.8s so the operations of the scuttle vent is not needed for comfort but it would be nice to have every feature of the car still work?

 

I have a good used vacuum servo used in the 1963-1968 S type. it has two stubs on the rear where it mounts to the firewall/bulkhead, and it has a long linkage that connects it to the scuttle lever. at the bottom center there is a nipple for a 1/4" vacuum hose.

those were GM or Studebaker or Packard vacuum servos used in early Jaguar.

The XJ-6 Series 3 (1980-1987) uses a similar vacuum valve/servo for the center interior vent flap and also in each of the two blower cases.

To get to the center vent in the XJ-6, you need to remove the dash pad covering; The valve is visible at the top center from outside the car once the dash pad is removed. It mounts the same way but with two phillips screws, and the linkage attaches in a different way, with a clip; also the vacuum hose nipple is 1/8".

below are pictures of the XJ-6 vent flap vacuum valve or "servo", a generic servo from Airtique Products, and another generic servo from cmwauto.com

the function is always the same: apply vacuum > servo/valve opens,
remove vacuum < servo closes. Note that some of those servos operate the opposite way, i.e., remove vacuum < servo opens. Those "reversed servos" were used in the Series 1 XJ-6 and 12.

 

Jose, much thanks! so you are saying an XJ-6 from 1980 to 87 will work? Do you know the best part number to use? so I assume you installed one and the vacuum is now working? I hope that is the case as my car just needs a new vacuum which I could never find until now?

 

primaz, I still have the original vacuum servo in my S type, I haven't replaced it, but the Series 3 XJ-6 has a very similar vacuum servo that could replace yours, (it is used to open the interior/cabin center vent, same principle), and I have observed domestic cars with similar vacuum servos. You could contact Airtique.com or cmwauto.com and see if they can match yours.

BTW, there is a shop in Australia that rebuilds these servos.

 

Jose,


Thanks, I just an e-mail inquiry to those two companies and I am crossing my fingers they can provide a new replacement vacuum device that will work. I would be fine installing a series 3 XJ-6 one if that will work but if I am installing something not stock I would prefer it to be new. Do you know the Jaguar part number? After searching for a while I found some used ones but thus far cannot determine the part number nor if anyone sells new replacements? Finding a replacement vacuum unit that is new is so so hard so far for me.


PS if you know the name of that place that will rebuild them and their contact information please let me know...

 

if you post a picture of your old vacuum servo it would help a lot.

 

Jose,


Here are two pictures (sorry they are not the greatest pics) of my unit, I thought you owned the same model Jaguar as mine? I circled the vacuum unit in "red" in the PDF version. It is the round unit about 3" diameter in the middle of the firewall, it is painted black. I will try to take a couple of better shots and post them this week.

 

yes I see it, yes, same as mine. Have you tested it to see if it is holding vacuum?
Easy to test without a vacuum tool: get a long piece of 1/4" hose, connect it to the nipple (where the existing hose is), and suck on the hose until you see the scuttle opening, then quickly put your thumb on the end of the hose and watch to see if the scuttle starts to close by itself, which would mean the inner diaphragm of the servo/valve is leaking. If it stays in place as you keep your thumb on the hose, then your leakage is somewhere else, probably the Brake Booster or the Vacuum Tank located on the driver's side fender/wing; Those vacuum tanks are known to rust and leak, there is also a 3-way plastic check valve connected to the vacuum tank which is known to leak too, and those are still available because they were used all the way to 1987 XJ-6. I have both a 1984 XJ-6 and a 1965 S type, and I see many identical hardware parts on the XJ-6 and the S type. The vacuum tank and the Brake booster can be rebuilt too.

 

here's one on eBay: (came off a MX-10 but the principle is the same).

Jaguar Cowl Vent Vacuum Assembly for MKX 420g May Fit 3 8S 420 Works Well | eBay

 

FYI the Jaguar part number for this item is BD25328. Unfortunately this item is unavailable to our knowledge, we have no supply. Hopefully the part number will help you locate one.

 

Thanks for the part number; I am aware Jaguar sourced many parts from US companies, Ford, GM, Studebaker, and Packard;

examples:

in the 1963-1967 S type and also the 420, the Power Steering System was a Ford system used in Ford Tractors (yes, Tractors). You can find parts and filters for this system in Ford Tractor Supply stores; The S type transmission was a Studebaker DG-250, and rebuild kits are available from DG-250 parts suppliers.

and all the way to the Series 3 XJ-6/12, many GM parts were used: Delco ignition parts, Borg Warner BW-66 transmissions, GM Harrison a/c compressors, GM/Delco check valves, and so on.

my point is that this Vacuum Regulator (called a "Servo" in the UK) might have come from a GM supplier; Therefore it might be possible to obtain a regulator that does the job, from a classic GM car;

considering the original part used in Jags is no longer available, we have to make do.

take a look at the following link and you will see similarities of design in the 1960's vacuum regulator for a GM car. With a little modification, these Regulators can be made to work in the S type/420.

Oldsobsolete | 1963 – 1964 GM Heater Selector Vacuum Valve Actuator NOS # 1998900