My 3500s project - future daily drive


Well-Known Member
Yes heat soak caused your vapour lock problem but this may not be a direct relationship to the Block or radiator temperature but rather an under bonnet air temperature issue.
I know that may sound a little pedantic however the cure whilst it may be affected by upgrading fans and radiator to an extent. probably the vapour lock issue is better addressed by re-routing the fuel lines under bonnet or providing cooler air to those fuel line componants.
Good tried and true advice is to upgrade to a 3 core radiator as the engine cooling in really hot weather is a little marginal, a combination of this and the above re-routing will I am sure see a 100% effective cure.



Active Member
The fuel sender is easy enough to remove when you've drained your tank. Disconnect the fuel lines and remove the lock ring - ploop! out it drops. wouldn't mind betting it is in similar condition to mine, which was a rust-encrusted piece of non-working crap. I cleaned it all up* and tested the resistive wiper - it was fine - and it then behaved well until about March this year, when it started reading 3/4 when the tank is full...

*I removed the fuel tank and cleaned it out too, using the stones and shaking method.
The very first thing to do when you get vaporisation is not to run straight into the arms of that nasty Mr Facet! It's to check the coolant outlet from the inlet manifold. These get blocked with all kinds of crud accumulating in the "tower" between the two carbs. Get the pipe off there and see if you are getting full free flow of coolant and that the pipe to the top of the rad is not collapsed. Any doubt and insert a small strong jewellery screwdriver into the tower. It should go a long way in. If it doesn't, encourage it vigorously with a sledgehammer!

Build up of heat in the tower leaking out to the carbs is what causes vaporisation. The temperature gauge is no guide to what is happening there as it measures the main engine return after the thermostat. For this reason a three row radiator core is another good trick to eliminating vaporisation. The coolant delivery to the engine is thereby somewhat colder giving that which reaches the tower more of a chance. It doesn't affect the rest of the engine or the gauge because they are looked after by the thermostat. You commented that your radiator was looking tired. Get it rebuilt at a local radiator shop - they do still exist because of the needs of construction plant and trucks - and they will be able to fit a three row core to your existing tanks.

Of course, electric fans won't have any impact on this problem as they are essentailly merely controlling the main return temperature. But they are brilliant at liberating quite a bit more power and reducing fuel consumption when you throw away the engine driven fan.

If you do end up going down the electric pump route, then don't fit it at the back. Fit it behind the left front headlamp. Then you retain all the existing pipework and the main reserve changeover valve. Try not to use rubber fuel hose in the mod. We have recently seen a piece of hose under a year old and sold as being compatible with E10 etc that has literally come apart at the seams with the rubber cracking all the way down its length. It leaked in mid pipe! We prefer a HUCO rotary pump to the facet. Although it is possible to buy a low pressure (for carbs) facet, most people seem to end up with a high pressure one and a fuel pressure regulator. This is not a good idea. A recent engine fire seems to have been due to the regulator dissassembling itself....

Ron mentioned the output shaft oil seals on the diff. Far more vulnerable is the seal at the front of the diff extension. Once you've got the four hole yoke off the end, it's very easy to change. I have seen one car that didn't have one fitted at all from factory....

Hope that helps

Thanks for the replies everyone - as usual a mine of information. Where to start? Please accept my apologies for such a long and rambling post, one with an almost total lack of pictures. As an extra note the car does not vapour lock when running, it has been idling happily for long periods in bumper to bumper traffic this week, it seems that the heatsoak from the switchoff may have been too much though and the location of the lines can't help.

Ok, heres the status of everything cooling related, so you guys have a better idea of what I have done so far (These all before the problem). Hopefully I have most of the basics covered - tell me if I have missed anything :| :

• The rad has been flushed, and a lot of limescale removed, the rad has a new 15psi cap as the old one was lifting at the drop of a hat. I am using blue MEG type antifreeze at a 33% solution with soft water (my dehumdifier died recently, which is a pain). The fins were initially full of cobwebs and fluff, but this is clear now. It does look a little tired, but is better than I first thought. Far better than the radiator on my 90, which has hardly any fins left.

• All the coolant hoses are new, including the pump bypasses, the heater lines and the carb tower outlet.

• The carb tower is clear and free flowing - it wasnt when I got it, and it required some careful drilling :shock: to get things to flow.

• The thermostat is an 88 degree one with jiggle pin, and is fitted with the bleed hole at the 12 o'clock position (it was at the 9 o'clock position when I got the car).

• The system has been bled of air fully, with the car parked nose up on a slope and the rad cap off until the thermostat opened, and revs then picked up slightly for a minute or two before being finally topped off. The car has not dropped any water since initially purging the excess from where I had filled it to the top. The heater works brilliantly so that would imply that there is no airlock.


On Friday afternoon I drove from Weybridge to Farnham - a distance of 25 miles, with a 10(ish mile) stint down the A3 at 60mph, followed by the inevitable crawl through the rush-hour traffic at Guildford and up the Hogsback. The car performed flawlessly, and even though the temperature was again in the 30's it didn’t miss a beat, until I got home and parked up. Went to go out in it 10 minutes later and it wouldn’t start, no fuel.

I figured at the time that the mech pump had died after being unused for such a long time and then being asked to provide fuel for my jolly down the A3. On Saturday morning I fitted the old Facet from my 90 to the car. This was the factory fitted pump and fed the original 4 cylinder, and then the V8 happily for many years.

Bearing in mind that this was a temporary “try it and see” thing I plumbed everything in such that none of the original pipework was altered, I have it all in a Jiffy bag in the boot to go back on if needed.

Using a selection of preformed lines and a couple of short sections of SAEJ30R9 injection hose that my Dad had lying about surplus to requirements (my parents house is an Aladdins cave of landrover spares) I removed the feed and filter from the pump to the carbs, I routed the output from the mechanical pump to the Facet, before jumping back across and to the carbs, via a new inline filter.

The pump was secured to the wing, just behind the washer bottle. This worked and the car started, happy days I thought, but no!

On the Land-rover the Facet is mounted down by the tank in the rear drivers side wheelarch, and is really a pusher pump. It is fed via the pickup that exits the top of the tank, via a filter. The line then runs forward and up the bulkhead making the jump to the engine at the rear and running along the inlet manifold to the first carb. This keeps the length of fuel line exposed to the heat of the engine bay to a minimum:

I am thinking that I may replicate this, moving the pump to the rear (again with no permanent changes to the current pipework, so I can revert if needed) so that:

a) The pump is working as it was designed, pushing.

b) It would be pushing cooler liquid fuel to the front, which has to be easier to do rather than trying to pull hot fuel forward that is probably bubbling from the beginnings of vaporisation.

If this works I can then move my reserve tap back and fit a longer operating cable I guess. This would also allow me to work the reserve tap into the low pressure side of any EFI fuel system that I fit at a later date. I really like the idea of the reserve and would hate to lose it.


My Dad has a 10 Ton press, but I don’t relish the idea of removing the diff to get at everything. How long would you chaps estimate for it to take somebody on their first go? Just planning for the worst here in case the breather is clear. Hopefully it’s the breather though, or the seal Chris mentioned…


Thanks for the advice Warren! I am hoping to get to look at it all tomorrow, but work may have other ideas- assuming a brimmed tank you should normally have 56 litres and then 12 in reserve right? I am just running around with a 20l jerrycan in the boot and keeping an eye on the trip counter at the mo. Not the most relaxing way to travel, even in a quiet and comfortable car like a P6... :roll:

Onwards and upwards!


Well-Known Member
Staff member
Hi Quagmire,

You don't need to remove the entire diff to change an oil seal. If the pinion oil seal is leaking, then the oil will be on the bush and around the crossmember, it won't be on the diff itself. If the oil is on and below the diff, then a drive shaft oil seal is the likely culprit. Having a squizz underneath will reveal all. :wink:

Fuel vapourisation problems can also be a function of the grade of fuel that you use and the time of year. If I use 95 octane fuel in anything like warm weather, especially just after Winter, my Rover will suffer vapourisation issues. If I use 98 octane fuel, it doesn't.

Right then. So basically you've got everything right apart from the upgrade to a three row rad.

Next port of call is a system chemical clean. Try two bottles of Tesco or similar dishwasher cleaner ie for cleaning the dishwasher, not cleaning the crockery, dumped in the rad and allowed to brew for a while wih a running engine to circulate it. Can be quite spectacular with a warm engine. The logic for this is that you mentioned limescale in the rad. So it must also be all round the rest of the system. Dishwasher cleaner will shift it a treat!

After that there are a couple of little tweaks to just enhance things slightly. Reroute the fuel supply from the reserve tap to run all the way across the back bulkhead and behind the steering idler. Then come up onto the top of the inner wing and run approximately where the wiring loom runs to the front, down and jump across to the pump.

PLEASE use metal pipe for the sections of the run on the body. It's dead easy to get hold of a roll and a flanging tool. Rubber pukka fuel hose has some duff batches going the rounds at the moment where the structure of the rubber fails within a year leaving you with leaks out through the fabric web armoutring within a year - in mid pipe! And it would be much better to use a high pressure fuel pipe with proper screw up terminations for the flexible at the front where it jumps across to the engine - injection pipe for instance.

Next trick is to ensure the air can get out from under the bonnet while stationary. First make sure the blanket is firmly attaached to the underside of the bonnet, or even discard altogether. Then raise the back of the bonnet very slightly by adding washers under the hinges. The idea is that the engine bay heat can escape down the sides of the bonnet when staionary.

You've got the right agenda for the pump you currently have, but I'd still prefer to use a HUCO.

All basically common sense, but the thing is so marginal that little improvements just tip the balance.

Just as an aside, the US spec 3500S Auto destined for California with the exta heat load of an A/C pump had three scoops on the bonnet. Whilst the centre scoop was as you would expect - an air scoop feeding into the carbs, the outer two weren'to get air in, they were to let air out when staionary. There's nothing new under the sun!

The P7 (lengtheded P6 with a six pot version of the 2 ltr engine) had vintage style louvres up each side of the bonnet for the same purpose. I can tell you they look good on a P6 as well, as I have them in my soon to be fitted spare bonnet.

Went over to my parents this evening after work and got the car on the drive and onto the ramps so I could prod around underneath...

The patch of fluid I saw was not oil from the diff - its brake fluid! The drivers side is leaking. :cry: bummer!

Looks like a pair of recon calipers is in order, I have rebuilt Landrover calipers before and although straightforward it was fiddly.

On a positive note I have figured out how I am going to do the rear mounted fuel pump after offering it all up, and also proved that the Disco fan I picked up from my brother can be mounted as a puller.

Looks like I am back driving the 90 for a little while then.

Updates to follow when I make some progress. It'll either be very quick, or take a month or two as we are moving house in something like 28 days. :shock:
Small update:

Rear calipers replaced with recon units from MGBD, along with new pads at the weekend. What a bu**er of a job! I have been spoiled with easy access on the landrovers and so spending most of my weekend on my back (and not in that way!) was not fun. All done now though and no more leaks, and after 150miles they are feeling good. :D Couple of questions though:

Handbrake is pretty poor,holds the car but only just. I should have done the Harvey method and offered the discs up a few times, in between operating the quadrants by hand with the linkages off but hindsight is a wonderful thing :oops: . I simply cranked the quadrants by hand with the discs in place and linkages disconnected. I plan to redo this when I next get an opportunity.

However, I believe that the handbrake cable should be slack enough so that when everything is connected the quadrants are back on their stops. My cable is too tight, and the quadrants sit about 1/4" off the stops. I looked at slackening things off, but two things - firstly I only have about 5mm of thread left on the adjustment which I dont think will be enough, and secondly how the flip do you get up past the exhaust and the prop to get to it? I am thinking of buying a spanner I can cut down as all the ones I tried were too long and I couldnt get a swing on it...

Suggestions gratefully recieved!




Well-Known Member
Quagmire said:
However, I believe that the handbrake cable should be slack enough so that when everything is connected the quadrants are back on their stops.
Correct, no slack, but not so tight it holds the quadrants off their stops.

Quagmire said:
My cable is too tight, and the quadrants sit about 1/4" off the stops. I looked at slackening things off, but two things - firstly I only have about 5mm of thread left on the adjustment which I dont think will be enough,
Your adjuster nuts will be at the front end of the threaded section, moving them towards the rear of the car will move the quadrants back.

Quagmire said:
and secondly how the flip do you get up past the exhaust and the prop to get to it? I am thinking of buying a spanner I can cut down as all the ones I tried were too long and I couldnt get a swing on it...
I've got a cut down spanner.....


Well-Known Member
Quagmire said:
Handbrake is pretty poor,holds the car but only just. I should have done the Harvey method and offered the discs up a few times, in between operating the quadrants by hand with the linkages off but hindsight is a wonderful thing :oops: . I simply cranked the quadrants by hand with the discs in place and linkages disconnected. I plan to redo this when I next get an opportunity.
In the meantime you could try the simpler method and removing only the outer pad instead of the disc. Maybe it's not as effective, but it is pretty close and far easier if you don't fancy removing the discs soon.
I'm afraid that hand brake cable needs tackling pretty quickly. With the quadrants off the stops, the self adjusting won't be working and it won't take very long at all before there's some kind of accident inside the caliper as a result of too much piston travel to get the pads in contact with the discs.

Thanks for the replies guys, appreciated.

No fear on causing a failure in the handbrake, at work I am in a dead level space so only a couple of clicks required, and at home its not too bad either although it is a slope so I have been leaving it in gear - again with minimal handbrake on.

Driving about I am one of those annoying souls that sits with their foot on the brake pedal. Not so bad in a P6 though as you arent blinding the person behind with an uber-bright high level brake light like the moderns have.

I'll see what I can do this weekend with the outer pad removal method and slackening the cable, moving house in 9 days now so a proper adjustment will have to wait a week or 2. If I cant get much improvement I'll have to take the wifes Polo and she will be relegated to the Landrover again, that will make me popular! :wink:
You're missing the point slightly there. The handbrake cable holding the quadrants off the stops prevents the adjustment of all of the mechanism - footbrake as well as handbrake. It's all in one simple (?) unit to do both functions.



Active Member
You're right to add in that question mark, Chris. I rebuilt my rear calipers, and they were certainly clever, but I'm not sure about simple...


Active Member
Well, long time no update due to moving house:

How many boxes can you get into a 90? Quite a few:

But you can get more in a 101, and a lightweight helps too (arriving at new house):

P6 in its new home:

But in amongst all that I have now covered something like 2,500 miles since the car passed its MOT. Will be due another oil change in a week or two.

I have over the last weeks done the following:

Slackened off the handbrake cable as per Harveys post, just enough until the quadrants were on the stops. The handbrake has since adjusted up nicely and holds well as it did before.

Fitted a new throttle spindle bush on the bulkhead.

I then started losing hydraulic fluid again - but not from the brakes, the clutch master had gone. Not too big a problem, as I had seal kits for master and slave on hand. Luckily I decided to check the slave while the system was dry, and I was glad I did, as it had just started to weep. Back when I got the car and freed the seized slave off to get the car moving I had no choice but to use the old seals again, and they obviously had decided enough was enough too.

I also have fitted an electric fan, (although this has been on a while now) in sucker mode. The fan is a 12" from a MPi Discovery. I retained as much of the Disco cowling as I could and it seems to work well, holding the underbonnet temps down on all but the hottest (30+) days. When it gets that hot the temp will slowly start to rise until I get moving again. This is controlled manually at the mo, hence my question on the internal diameter of the bottom rad hose over in the V8 section. Its definitely a squeeze as I have only about 4-5mm between the back of the fan and the roll pin that sticks out of the waterpump nose. Close, but not touching!

I was getting a sight hesitation at when trickling along on light throttle at say 30mph in 4th and then prodding the go pedal. I figured it would either be ignition too adanced or mixture too lean. Timing was checked and found to be OK. I then took the next easy step, and tried changing the dashpot oil in the SU's from ATF to 20w50. The car now just hunkers down and gets on with it :mrgreen:

I have also started collecting the bits I need for fuel injection and crank triggered ignition as I have a spare Megajolt unit (which will be the first step before going to MS) but thats still a loooooong way off.

Fuel consumption continues to be good, with my highest attained figure for a tank at just a tiny shade over 26mpg!

Next things on the list to do are:

  • Fan controller
    Electric fuel pump to be moved to rear mounted position, with reserve tap
    Header/Expansion tank mod - I have the MGB style brass tank ready to go on and a blank rad cap.
    Fuel sender needs investigating
    Buzzer to remind me to switch lights off
    Change alternator, rebuild existing one as a spare for the shelf.
    Finish lapping in the valves on my 10 bolt heads so they can go on
    MP3 conversion for radio

I promise better pictures in the next post!
Quagmire, that is one hell of a collection of Landrovers there. A lightweight, 101FC and a 90 all in one spot. Very nice.

I still miss my J plate 109" SIIA (plastic grille) which was my first car.. 23 years ago now - EEK!