Get the splined removal tool, new chambers, copper/soft steel sealing washers and o-rings AND some copper antiseize compound. Forget the glowplugs if the chambers to fit them are not easy/cheap to get. Use the standard chambers and keep a can of starting fluid/ether for the times when it needs a little help.

If the chambers do not break loose and come out easy, stop and screw back in, back out until it binds, back in, back out etc. This may prevent removing threads from the head. The chamber threads don't matter, you are replacing them with new anyway, but saving the threads in the head is well worth taking some time removing the old chambers instead of just removing them with brute force. If the threads in the head are damaged beyond cleaning up with a tap, they could be repaired with an insert or perhaps drilled and tapped to take the D315 chamber as mentioned earlier.

In any case, an application of antiseize to the threads of the new chambers is a very good idea. I like the copper type antiseize because the washers are copper or sometimes copper plated soft steel.

The picture attached is from a later (early 1960's) version of your D311 engine, but should illustrate the assembly adequately for your purposes of removal and replacement. Do not use the part numbers shown without checking they are correct for your late 1950's engine.

Edit......looking at your photo, the chambers may be fine, just need new seals and perhaps cleaning up the seats in the head where the seals touch. There may be a kit with a stack of several different thickness copper washers/seals to use so the glowplugs do not stop where they will interfere with the injector fuel lines. If the glowplug hole stops in the wrong area, remove and replace copper seal with a thicker or thinner version to move the glowplug hole.

With the head removed, you might help chamber removal by brushing away the carbon and spraying some type of penetrating oil into the threads on the tip of the chamber that shows in the top of each cylinder.

"ccjersey" wrote:

Get the splined removal tool, new chambers, copper/soft steel sealing washers and o-rings AND some copper antiseize compound. Forget the glowplugs if the chambers to fit them are not easy/cheap to get. Use the standard chambers and keep a can of starting fluid/ether for the times when it needs a little help.

If the chambers do not break loose and come out easy, stop and screw back in, back out until it binds, back in, back out etc. This may prevent removing threads from the head. The chamber threads don't matter, you are replacing them with new anyway, but saving the threads in the head is well worth taking some time removing the old chambers instead of just removing them with brute force. If the threads in the head are damaged beyond cleaning up with a tap, they could be repaired with an insert or perhaps drilled and tapped to take the D315 chamber as mentioned earlier.

In any case, an application of antiseize to the threads of the new chambers is a very good idea. I like the copper type antiseize because the washers are copper or sometimes copper plated soft steel.

Thank you. I will head down to the CAT dealership tomorrow and get the splined tool. Would you advice to change all the chambers and get new ones?

As per bcwayne's comment, how hard is it to rethread and refit the D4's chamber into the D2, in case I can't find glowplug chambers?

"bcwayne" wrote:

I believe a late model tractor will have the pre-combustion chambers that take a multi spline tool to remove and install, not the hex style as found on earlier tractors, and that with direct electric start, it will take the pre-coms that have a glow plug... no longer available. But a D4 chamber can be re-threaded to fit. A search of this forum will provide the necessary details.

The shop you mentioned that works on heads may have the tool you need and would certainly be a good place to consult about this problem. CAT used precombustion chambers that are removed with the same splined tool on many engines for many years. Very common.

If the chambers are not pitted, the sealing surfaces are good or can be cleaned up so they seal well and the threads are in good shape I would certainly reuse them. The earlier style chambers were made of much thinner steel and commonly corroded through if the coolant was neglected. Those chambers probably weigh 3 times what the early/ non-glowplug style weigh.

"ccjersey" wrote:

The shop you mentioned that works on heads may have the tool you need and would certainly be a good place to consult about this problem. CAT used precombustion chambers that are removed with the same splined tool on many engines for many years. Very common.

If the chambers are not pitted, the sealing surfaces are good or can be cleaned up so they seal well and the threads are in good shape I would certainly reuse them. The earlier style chambers were made of much thinner steel and commonly corroded through if the coolant was neglected. Those chambers probably weigh 3 times what the early/ non-glowplug style weigh.

Thank you, since they're near I'll check with CAT first, if the tool is cheap enough (like < 10€) I'll just buy it. If they want to charge too much for it, I'll check the shop, see if they have a tool that fits.
It is like a bolt, so I'm guessing they won't charge more than 5€ for it.

Well, at least some of the chambers (or the head) is leaking coolant into the cylinders, so something is up. Honestly, I'd prefer if it was a chamber instead of the head itself.

Would this chamber fit? parts.cat.com/en/catcorp/2S-1273
I saw it here: www.costex.com/pre-combustion-chambers-f-720-099/ that that's the chamber for the D311 engine

I'll ask CAT tomorrow, with the S/N, which chamber is right, if they still have it, and how much is it, just to have a quote.

By the way, from the S/N, can you give me an idea of the year the tractor was manufactured? 50-55? I know I already asked 3 times

D4 glow plug chambers are 1-1/8 tpi, D2's are 1-12 tpi
D4 chamber threads can be recut to the 1-12 tpi

Taping the D2 heads to 1-1/8" 12 tpi does not work because the 1" major thread diameter is larger than the 0.9394 minor thread diameter required for the 1-1/8" thread.

&quot;dwjorgeb&quot; wrote:

By the way, from the S/N, can you give me an idea of the year the tractor was manufactured? 50-55? I know I already asked 3 times

S/N 5U16679 per ACMOC Serial Number Reference Manual is 1955.

Daron

&quot;daron&quot; wrote:

S/N 5U16679 per ACMOC Serial Number Reference Manual is 1955.

Daron

Thank you! Any other info on that manual?

It is just a serial number by year reference for CAT equipment. Sometimes has mistakes on some of the more obscure types of equipment.

If your CAT dealer is like ours, their parts look up system will be on a computer for the modern machinery they deal with every day but require them to get out paper parts books or go to a microfiche viewer to look up parts for your machine. Sometimes helps to get the oldest guy available to help you! Last time I was in, I got the youngest 20-something, but he was very helpful (attitude is everything). Only problem was they had little of what I needed in stock!

Hey guys, so I went to the CAT shop today and they let me borrow the tool to remove the chambers.

I removed them, scrubbed them a bit but they don't seem to have any holes or gaps. One of them is definitely older and more beat up than the others, but they don't seem to have any problem (at least to the naked eye).

What else could it be to let water / coolant into the pistons?

Should I reattach the chambers (with new washers) and take the head to the engine rebuild shop to get it tested?

Thank you for your help

That sounds like a very good plan. Have them check the head is flat and the valves all seal properly as well. I think its best not to grind the valves unnecessarily as it lowers the compression ratio slightly unless new valves and seats are installed.

Some of the higher HP engines tended to have exhaust valve erosion of the stem just above the head and as a result they would "drop a valve". Someone that has looked at a lot of heads should spot things like that.

Did you check the chamber and seal for the cylinder with the water especially carefully? Usually a clean surface with no carbon on head and piston top is a sure sign there has been water leaking in that one for a little while.