95 Disco coolant bleeding

[tuckerboy]

hi. just bought my first disco and the front heater doesnt work.
the blowers work fine, so i suspect an airlock in the water matrix.
now i aint no mechanic and can just about check the oil level :) so please go gentle.

could you tell me how to bleed the coolant matrix and where about seach part i need to know is.

the disco is a 300tdi

cheers
( a step by step idiots giude would be very much appreciated.lol)

[ComicalEngineer]

Obvious stuff first:

Have you checked that there's enough water in the system? The level should be about half way up the header tank. If it's like mine, that's the black one on the L/H side (looking from the front) of the engine bay and just in front of the wheel arch. Mine is black, some, I believe are translucent. If full to half way, proceed to step 2, otherwise fill up with 50:50 antifreeze/water mix.

Secondly, undo the black plastic plug on top of the thermostat housing on top of the engine - CAREFULLY - because they have a nasty habit of shearing off. Do a search for plastic plugs and you'll see. If the water level can be seen in the pipe below, then the system is probably full of water. If not then fill to the top with mixture as above. Let it settle for a minute or two and top up if necessary.

No bleeding of the system should be necessary. The other possibility is that your thermostat is stuck open. Can be seen by the temp gauge not getting warm unless you're charging down the motorway.

In which case see this:

http://forums.lr4x4.com/index.php?showtopic=10681&hl=thermostat

Acknowledgement to the great Les Henson, I borrowed your photo from the tech post on replacing the thermostat.

[MarkWillenbrock]

It's not hard.

To the best of my knowledge, there is no separate bleed for the heater, just the main one on top of the thermostat housing. Air could cause your poor heater - but it could also be the thermostat. Either way, you won't loose anything by trying to bleed it.

Step 1. Cold engine. It may be that it should be warm to get the coolant circulating through the radiator, but you can also get burnt. Others might correct me on this?

Step 2. There's a big black plastic plug on top of the thermostat, put there by LR for this purpose. How Thoughtful. Procedure is:

a) Apply socket or screwdriver to plug
b) Find plug shears in half
c) Find no one has one in stock
d) Kick Land Rover

Alternative Step 2. There's a small bore rubber pipe that runs from the thermostat housing towards the coolant tank (it joins a similar pipe from the top of the radiator on route).

Remove the pipe from the thermostat housing - it has a small jubilee clip. If the pipe splits or whatever, you can shorten it and reattach it. Might be an idea to have a spare jubilee clip on hand.

Step 3. Take the cap off the coolant tank. Have some antifreeze ready.

Start the engine. Run back around to the front of the vehicle. I normally fall over the can of antifreeze at this point.

You might find nothing but air coming out of the nozzle on the thermostat housing. If so, fill the coolant tank with antifreeze.

As it fills, it should push air out of the system. Hopefully you'll get a few spurts then a solid jet of water from the nozzle.

Step 4. Jam the pipe back over the nozzle. BE VERY CAREFUL ABOUT ROTATING FANS, BELTS, SCALDING WATER ETC.

Step 5. Realise you put the jubilee clip to one side, so you have to repeat the entire process.

Step 6. Take it for a spin and try and get the temperature up and the thermostat open. A long motorway hill is ideal.

Park it up and check the coolant level the next morning.

Note that on a Disco 300Tdi it makes no different where the heater controls are, but if in doubt or on a different model, set to full hot.

[tuckerboy]

thanks

right.. i got the plug open on top the houseing. kindley some one already did away with the plastic one and replaced it with a metal one.

the fluid level was no where near the top so im going to now try toppin it up. hope this works.

any more suggestions

[MarkWillenbrock]

Yes - run the engine as you fill

[TEMPL4R]

If someone has drained the system, the 300s tend to airlock where the heater pipe curves down and joins the bottom hose.( If the heater pipes are on the wrong way, they air lock.)

You can undo the join and pour water into the header tank until it comes out of the bottom hose, cover that with your thumb and keep topping up until it comes out of the heater pipe. Join the two and away you go.

PS do it cold.

You should also make sure the bleed pipes get hot.


Just a thought, has it had a new water pump? That is a common failure on 300s.

Chris

[tuckerboy]

ive only just bought the landy.its has got full LR service history up to 10,000 miles ago.but doesnt seem to have had a new water pump.although it did have a new head not long ago i think.

[TEMPL4R]

In that case, make sure the pipe from the bottom hose, along the side and the back of the head, goes to the top heater connection.

Chris

[tuckerboy]

dumb question i know. but where do i look to find the heater? :D.. i did say im no mechanic..lol..

[MarkWillenbrock]

The two pipes that go from the back of the head into the bulkhead

[mjw]

hi ya i had a similar problem when i first bought my disco 300 tdi,
i found that the thermostat was taken out! why i don t know.
my heater only ever got luke warm at best even though temp guage went to nornal.
replaced the thermostat (just two bolts), blead the system as others have described and no more problems now for 6 weeks +

hope this helps

[tuckerboy]

thank you all for your help.

this morning.after spending all last night bleeding the system, i found the two pipes that run along the head. only to discover that they wernt even connected to the heater matrix and were joined togetehr with a piece of brass piping.
i got a bit suspicious and so rang the previous owner to see if this was done because the matrix leaked.
he told me that the landy was parked up since it was last in the garage having the head done. and was working previous to that. so maybe the garage was lazy and didnt bother connecting it back up to the matrix.

so i re-connected the pipes and took her for a spin. only to find i soon disapeared in a thick cloud of steam where the coolant/water was pi**ing into the foot well from the leaking matrix. bloody great.

ive since been to my local 4x4 garage and have been quoted £170 for the new matrix and labour. (is this reasonable????)

contacted the previous owner and asked if we could come to some sort of deal over the bill.. hes getting back to me after hes spoke to the garage that did the head. as before it went to them it worked fine. he suspects they preasure tested the system and in doing so cracked the heater matrix. (would this happen???) and instead of telling him about it and fixing it,they have joined the pipes together by-passing the heater matrix.:(

[MarkWillenbrock]

Call me cynical, but I don't believe he didn't know. Very handy that he coincidentally sold the car straight after, presumably without even noticing the heater didn't work - must be that heat wave you're having...