Here is the aftermarket servo I'v acquired for my 1959 Mark 1 with disc brakes: http://www.sngbarratt.com/English/#/...y=BRAKING(1179)
the installation instructions with this unit calls for the vacuum hose from the intake manifold to be directly connected to this new unit. My question is : CAN I BYPASS THE JAGUAR'S VACUUM RESERVOIR ?
I would like to do this for a couple of reasons. one, its a simpler installation and two, looking at the condition of my current reservoir tank and associated connections I'm guessing that this would need some major R & R before I'd trust it to function as intended. I'd like to keep the mechanic's expense on the servo installation to the minimum by just eliminating this reservoir system. Now, I can conjure up a scenario in which I would want to have the additional safety of the vacuum reservoir available - but those circumstances are (hopefully) very unlikely in real life driving.
Gentlemen, thanks for your thoughts and insights.
Schmitty

 

Modern cars don't use a vacuum reservoir. A few Mk2 owners have omitted them. Without one, you have fewer assisted pushes on the brakes after the engine stops. I've never tried to run without one; I repaired the tank.

Before doing anything that might be interpreted as a safety downgrade, I'd try to find out the attitude of my insurance company.

If you connect 'directly to the inlet manifold', most certainly don't omit the one way valve (there are a lot of very good modern ones in nylon that fit and cost less than the 'looks like' OE). And finally, you've spent a lot of money on the servo, is the cost of making a good installation with a restored vacuum tank a significant additional expense?

 

Peter, thanks for the reply ! you raise good points. If I had access to a lift and then could remove the tank, clean it up and repair whatever needed to be repaired, I'd do so. Howerver, I don't want to pay the high mechanic's hourly rate to undertake this unless absolutely necessary. My kit did not come with a check valve, nylon or otherwise, so I will try to get one. I've made a quick search of SNG and Moss and am unable to find such a valve. By any chance do you have a recommendation site or product ? I will do further research before committing to one way or the other

 

Schmitty, It's 40 years ago that I replaced the check valve on my car. I think the valve I used was a fairly standard one used by British Leyland at the time.

 

I would not do away with the vacuum tank. They come up on eBay frequently. They are GBP 95 new.

Here is one for 30 Pounds. Have a look your side of the pond. Do not omit the stone guard.

https://www.ebay.co.uk/itm/334431535...Bk9SR-Com4H9YA

 

I had a look at the SNG Barratt website. They list a check valve at over £40 (UK site). It's a 3 outlet device as it's also the connector to the reservac. If the one on your car has failed, it's still possible to use it as a connector and add a cheap generic one in the vacuum line from the manifold. The only requirement for the valve is that it matches the bore of the vacuum hose. Spares shops should have a selection. Access to the reservac and the valve is not difficult as they are near to the servo under the right fender. You/your mechanic will be in there anyway to swap the servo.

 

I was about to say check valves are readily available at Barratts & always have been..

 

As far as vacuum tanks, I use the black plastic sphere that the General used all trough the 70s and into the 80s. An easy to find and easy to pull part.

 

Do not omit the stone guard!

 

I omitted the stone guard, or at least truncated it, as it's another mud and rust trap. I replaced it with some thick, bituminous felt stuck directly to the reservac. That was after carefully cleaning and painting the reservac in 197?.

 

That is a very good idea Peter. It is still protected from flying stones kicked up by the RHS front wheel.

 

I've had a look at my reservac. I used the old, failed check valve as a 3 way connection and added a generic check valve in the vacuum line from the manifold. None of it looks too bad considering it's not been touched for more than 40 years almost 10 of which were in a particularly humid garage in the Netherlands.

 

So, the reservoir tank on my '59 Mark 1 is a rather large cylindrical affair that lays horizontal in front of the servo (behind a stoneguard metal flap) it only has two lines attached to it - no check valve device. the parts catalog for my car shows something that looks like the pics that have been posted here in this thread. So, I don't really know what my tank is, or where it came from, thus I'd rather just bypass this tank and leave it alone to RIP. I am on the hunt still for a generic vacuum check valve and will visit (with some trepidation) a local auto parts store to see what they may have. If anyone has any suggestions, that would be great. Thanks for all comments guys !
Schmitty

 

It sounds as if it's a replacement vacuum tank. That's not a problem. With two connections, it can go in the vacuum line. The line would go:
manifold -> hose -> check valve -> short hose -> tank -> hose -> servo
For selecting the check valve, it's a matter of finding one with inlet and outlet that match the bore of the vacuum hose. They need to be a tightish push fit. Maybe take some hose with you to the spares shop? You can make the attachment secure with Jubilee clips or similar, not overtightened on nylon.

 

Standard mounting from wheel arch & engine compartment:

 

A friend who emigrated from Holland in the 1970s brought with him a 3.4 Mk1. it was originally LHD but it was converted to RHD in Australia but still retained the LHD dash panel woodwork.
I was giving him a hand (assistance) one day to put on new drum brake linings and I noticed that it did not have a vacuum reservoir.
I queried him on this and he said that it never had one.
He had acquired the car second hand in Holland and had owned it for some time before emigrating to Australia.
He was happy with the cars braking.
He only sold the MK1 early this year as he downsized into a retirement village and had no space to keep it.

LHD dash in converted to RHD car

 

This might have been possible in the Mk1 due to the dials being central but if you did not change the wood from LHD to RHD in a Mk2 or S type it would awkward trying to read your speed across the cockpit.

 

In a MK1RHD the closed glovebox is on the left and the open glovebox is on the right.
He never got around to putting the overdrive switch to the right hand side

 

Oh my! he must have had arms the length of an Orangutan

 

I think he rarely ever used the overdrive as it was basically a town car.
I vaguely remember a conversation on this point and understood his wife would select the overdrive "if he needed it"
An early form of CRM? (Cockpit Resource Management).
The CRM concept is to manage use all of the flight crew in their interlocking roles to the fullest extent.

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