Cat Thirty Oil Pressure

At the dealer for dyno testing I always used the calibrated gauges so I knowed where things were and I can,t remember if Cat sold that type but it seems our local truck and auto. parts store sold them here that we dealt with.Yes there is different types of them, some with low pressure maybe up to 30 PSI for fuel pressure etc. and some higher ones for engine oil pressure.I also had one of the lower pressure ones for turbo boost. Boost by lbs. is half what inches of mercury (HG) is that Cat uses for the specs. of turbo boost.

On my 2 Ton I used a Stewart Warner gauge, it's an older style face and reads 0-50 pounds which is perfect because my tractor runs at around 30-32 pounds.
It is Stewart Warner P/N 82207 and cost about $US50 here in Oz. I'll try and post a picture for you, my first time trying that here on ACMOC.
Mike

Tom - For a test gauge, look on eBay and you will find hundreds of new surplus, or NOS gauges for sale at any one time, for reasonable $$'s.
A good quality gauge will have oil damping, and a large dial, with the needle doing at least a 270° arc of the face, and fine graduation marks.

If you search for an oil-filled gauge, with a fine-graduation-marked face, that reads 0-30psi maximum, you will have a satisfactory gauge for testing.
You will then just need to organise a suitable length of hose and fittings that allows you to tap into an oil gallery, and lets you read the dial satisfactorily.

Cat introduced re-calibrated gauges in 1951, to more accurately show low pressures, because many operators and owners were concerned about low oil pressures.
The previous gauge was 8B2355, the new replacement was 7F9084. The 7F9084 reads from 4-11 psi in the marked "operating" zone .. whereas the 8B2355 read from 10-40 psi in the "operating" zone.

Cat consistently repeated the information, that the old Cats (both gas and diesel) do NOT rely on high pressure oil for lubrication .. but on VOLUME of oil provided to the working parts.
Thus, you can have idling pressure of 4-5 psi, even on the diesels, and Cat still regarded that, as highly satisfactory oil pressure, on these old engines.

Once the newer range of redesigned, high speed diesel engines, were introduced from around 1959-1960 .. these engines were designed with, and require, higher operating oil pressures, and 4-5 psi is most definitely inadequate oil pressure for them.
The newer, high speed engines (1800-2000 RPM) run at approximately double the oil pressure of the old diesel engines.

Yes, you will have to find the 7F9084 gauge, to be able to have the low pressure showing accurately. Besides, a Cat gauge always looks better, and more original .. although it appears that the 7F9084 wouldn't be correct original, it would more likely have had the Sylphon gauge?

Here's a scan of the relevant 1951 Service Magazine article, when the re-calibrated gauges were introduced.

http://i38.tinypic.com/2qna0pw.jpg

Here is that gauge 7b9084

http://www.machinerytrader.com/list/partsSearch.aspx?PCID=&dlr=&GUID=a149b2b091054d8e89b5db6fe70148bc&Manu=&Mantxt=&Mdltxt=&mdlx=Contains&PartNum=7F9084&btnPartSearch=Search&fullsearch=

I have an old original 7F9084 oil pressure gauge in good condition, if someone needs it contact me.

Tom,
do you know were the street pads can from?

Oz,
your wealth of knowledge about cats is very impressive, If you put all of you data in cd form i am sure you would have lots of buyers.
I am not sure what the BB users would do without your input.

I feel the same way about OM and SJ as well.
I guess all great mechanics have two letters in their BB name.

Erik

Try this place http://www.superiortire.com/products/track_pads/index.php

looks like they have lots to offer😊

It looks like someone found new old stock WW2 Cletrac MG1 pads, for that CAT 30. They look good on the 30.

Tom,

Oil gauge aside...that is wonderful looking tractor! The THIRTY has always been my favorite gas Caterpillar. It grows on me more and more. I think I would have one today but I don't have a trailer heavy enough to carry one.

I have two other restorations I must finish first though...but by then I may not want to tackle bigger projects anymore.

I sure like looking though...you have a beautiful tractor!

Maybe Erik will let me operate his this year! (hint hint) 😉

Pat