4x4 Mag - Technical Tips

Technical Tips

compiled by John Deaville and Graham Scott.

This is our new Question and Answer section developed in response to the increasing number of e-mails received relating to queries on "how to do" and "what not to do" topics. If you have a question relating to anything mechanical and off-road contact us at technicaltips@4x4mag.co.uk and we'll print your answer here.

I've just bought a Lightweight Land Rover fitted with a V8. I am having problems with it overheating. The electric fan is controlled by a switch on the dash. Also I have fitted a Pacet fuel pump under the bonnet. Is this the right place for it ?

First of all check to see if the radiator is not blocked and you are getting a good ciruclation of water. If everything is OK the next thing you require is an electric controlled thermostat for the fan. This cuts out the need for you to remember to switch the fan on before it starts to overheat. Have a look at the fan. Does it move enough air to cool the radiator and is it blowing the correct way into the engine and not out ? I run twin fans off a Talbot Express Van on my Bowler, and they cope well when off-roading or in traffic. As regards the Pacet fuel pump, this is best situated down by the fuel tank as low as you can get it without it getting damaged. This pump is better pushing than sucking fuel. Graham runs a Pacet on his Hybrid and has not had any fuel problems of any kind.

I've got a 1980 Range Rover fitted with an auto box and a 3.9V8 and I'm finding the brakes aren't up to stopping the thing. I want to place 110 calipers on the front, but they're single circuit. Can you help ?

Yes it's possible and worth the effort. Firstly remove the existing brake calipers and pipe work from the master cylinder. Fit the 110 brake calipers in exisiting mountings. If the dust shields are in place these need to be twisted out a little to facilitate fitment of the larger calipers. Renew all the pipework from the master cylinder to the rear and front brakes, the rear pipe goes straight into the master cylinder instead of the banjo fitting, and this does away with the valve assembly under the bonnet. The two front pipes then come out of the master cylinder and go to each caliper. Bleed the brakes all round and off you go ! You'll need to replace the brake pads too and the complete combination will give better braking efficiency.

I've just bought an old Range Rover (1973) for off-roading. I've sold my old Series II but still have a shed full of spares such as diffs and half shafts which I didn't need with the old vehicle. Will these fit in the Range Rover ?

All Range Rover and Land Rover differentials are inter-changeable with the exception of the Salisbury axles. However, the halfshafts are not interchangeable. Range Rover and Land Rover diffs come in different types and will interchange, but make sure you have a pair that are the same ratio. Some diffs are metric, whilst others are imperial. There are also 10 spline and 24 spline diffs and half shafts. So in theory the answer is yes, but be careful with compatability.

Having replaced some brake cylinder seals on my Series III LWB Land Rover I am having terrible problems getting a firm pedal. It's OK when pumped but goes straight down if only depressed once. Can you help?

Brakes on Series Land Rover can be time consuming to bleed. Jack the front of the vehicle up as high as you can safely. Proceed to bleed the brakes starting with the near-side rear, then off-side rear, then near-side front and last of all off-side front making sure there is plenty of fluid in the reservoir throughout the process.. Jacking the front of the vehicle up helps prevent air getting trapped in the master cylinder and thereby giving the symptoms you mention.

I've recently been off-roading in my Suzuki SJ410 and done some wading. However, when leaving the water the engine started to splutter and misfire for a short while. I think moisture got onto the electrics, what can I do to prevent this from happening ?

Always remember that most vehicles cut out as a result of the distributor cap and leads being covered in water, either splashed onto them from the fan or because not enough "bow wave" has been created. It's possible to resist the ingress of water to these components quite simply and cheaply. Using a car inner tube we can make a cover for the distributor cap. Firstly remove the distributor cap and cut a length of tube to fit over it and refit the cap. If the leads are vertical connectors pull the tube up and tie off with cable ties. If the leads are at right angles cut two slots in the tube and pull over the top making an envelope. Cut two small holes in each flap and fasten with cable ties.

My SWB Series IIa Land Rover has recently broken a rear halfshaft whilst I was towing my caravan off a site. Since this is a second car and not used for daily transport it's still off the road waiting to be fixed. I'm told this is a job which I can do myself. How difficult is it to fix ?

This is a job you can do if you have a reasonable tool kit and apply some common sense to the overall operation. However, if you're not sure of you mechanical abilities best to leave it to a competent garage to repair. In brief to do the job you don't need to remove the wheels or jack the vehicle off the ground. If the halfshaft is broken it's most likely to be the "long" one, not the short one. The half shaft is a two piece unit with a seperate hub flange. Firstly remove the hub flange, remove the dust cover the split pin, the castle fibre washer and undo the flange pins. Remove the flange and half shaft together and tap out the half shaft. It's wise also to inspect the diff and to make sure that no debris has been left as a result of the breakage. First of all drain out the oil from the differential. Undo the propshaft from the differential flange. You'll need to take out both half shafts to remove the diff. Undo all the 3/8 nuts around the diff housing, remove the plate and then wriggle and pull the diff at the same time. CAUTION : it is heavy and may emerge suddenly. Inspect diff for damage and refit in reverse order. Refit the half shafts. Always refill with new oil, this makes sure that there are no foreign particles in the oil.