Bedford 500 diesel help!

Purchased parts of Don Kyatt spare parts for bedfords in seventies and early eighties and they were very good ring up before 1pm and parts on plane to Tasie that night received about 10am next day.
Peter

Bedford 500, i cannot think what the item is called but someone on this forum will think of it, it is a container that you add a special fluid to and hold it the top of radiator with the water level down so it doesnt touch the item, and if the
water contains combustion gas the fluid will change colour, hope this may help last one i used come from repco

i dont recall to much with the diesel beddy but if the air compressor is water cooled it may be pressurizing the cooling system cheers don

Purchased parts of Don Kyatt spare parts for bedfords in seventies and early eighties and they were very good ring up before 1pm and parts on plane to Tasie that night received about 10am next day.
Peter

I must be more old school and must admit it is nice to be able to ring up and talk to someone about what parts you need, and the bloke at Kyatt's really knows his stuff.

Trevor

Bedford 500 the item is called a combustion leak tester, i think you will find them listed on ebay, at a reasonable cost.
Robert

Hi guys a quick up-date on what I have been doing.

Well since my last post I have removed the cylinder head. Whilst trying to chase up parts etc. I discovered that the engine is in fact not a 500 but a 466!

Like another user posted the engine does have two large "O" rings to seal between the head and the block at the rear. There was no sign that these were leaking.

However the head gasket itself does not seal any coolant jackets etc it only seals the combustion. So of course I was again scratching my head thinking how on earth is combustion pressure getting into the cooling system? The injectors have a copper "sleeve" that seals between the injector and the coolant! Apparently they also have an "o" ring on sleeve. Strangely this is not described in the workshop manual!

Of course the way the removal of the sleeves is described in the manual they end up destroyed! Fortunately I have been able to chase up a VRS and the 6 sleeves through a mob in Melbourne called Auto Surplus. They have been very easy to deal with and I would reccomend them to anyone.

Well that is the latest from me. Once again thank you for the replies.

Cheers

Hi Guys has been a while since I have posted anything or done anything for a variety of reasons.

However over the weekend 15th and 16th of June I put the cylinder head back on the 466.

I had the head surfaced as it was bent by about 25thou! And all the valves were re seated to specs.

New injector tubes were purchased at great expense $65 each and installed and new VRS was used.

After bleeding fuel system and filling with water it started nearly first kick! However you can imagine my horror and frustration as water started to flow out of the header tank exactly as it had done before!

Said a few choice words ran until hot set tappets packed up and went home to do some soul searching/thinking/drinking!

Now I need help! Real help!

I will try to paint a picture of what is happening so others may have an idea.

Truck is a 1968 TK Bedford fitted with a 70 series 466 diesel engine. Engine runs fine (even better than before with head work done!) however the problem is that I am unable to keep the water in the cooling system. If I fill it up from stone cold and have it full all the way to the header tank and then start the truck water begins to run back out at an alarming rate! The water isn't really flowing out with much force however if the radiator cap is put on even for a minute or two there is a great build up of pressure in the cooling system. When the head was off I looked at bores top of block for signs of damage etc and all seemed O.K. The other strange thing is that the temperature gauge will go up quite quickly and then proceed to overheat. The block will be "hot" however the radiator remains "cold" the bottom hose is warm and the top hose is cold! I have fitted the correct thermostat however even when it is removed I still have the same problem! Naturally you would think that by "revving" the motor, if combustion pressure was present in cooling system, that this would cause more water to be pushed out radiator header tank however revving makes no difference.

Here is a quick list of what I have done.
New radiator cap
New thermostat
Removed head had tested machined etc
Replace injector sleeve tubes
Flow tested radiator with hi volume pump appears O.K
No hoses being squashed or "sucked" in
Ran various coolant system flushes through it.

I am at a loss as to what is happening! Is it possible there is a pinhole in one or two of the bores? Is the engine block blocked not allowing enough flow? Is the water pump perhaps mis-behaving?

Any help would be most appreciated PM if you want and I will give ph number + location of truck if you are really serious!

Thanks in advance guys/gals
Cheers

pull the rad out take the tanks off and clean it properly double chech rad cap make sure it seats properly ie right length. take water pump off while rad is out impeller might have fell off. i dought very much its in the engine those 466s are bullet proof if it was a liner it would have water in the oil if all else fails pressure test the coolant system 20 psi see if u loose pressure or water good luck.

This might sound stupid if you do a coolant pressure test wind the motor/engine over and do it whilst the beast is hot as may be a crack in a liner sleeve bore had a similiar thing many years a go did not show up unless the piston was in the correct position and the whole thing was hot
Just a thought

Another thought (because I had this on an old Renault once) as SteveB suggested, did you bleed the air out of the head? (assuming it is like that)
Forgive me if you already did this. I expect it would have to be done with the engine running so the water pump pressurises the block and head. (that's how it was on the Renault, anyway)
Best of luck, Jarrod.