Hi Team,

Well I have everything buttoned up except I opened up the bottom hard line to the transmission line. I went to my local cat dealer parts department here in Kona and they cannot tell me with certainty what goes in its place... Pictures are attatched...


Serial # for D9G is 66A08405

I need this D-ring or O-ring.... The cat parts guy said they don't make a yellow d-ring. I suspect this is the original one and the background is when my trans/torque cooler leaked into the torque converter with water it flooded and started leaking from this line... I took this apart and let the transmission and water drain out... Now at 1,000 for t0-4 I want to make sure she does not leak after I put her back together....

Thank you team...ATTACH=CONFIG]87679[/ATTACH]

This is the bottom transmission line and for the life of me I cannot find it in my parts book and want to replace with proper part....

They use a square[four sided] black rubber 0-ring now instead of the yellow one. I dont have a parts book for the 9's, I'm sure Ole Magnet will have it. The D7E uses a gasket. Thats the suction line for the trans/steering clutch pump. Should be a 1P#. I would replace that coupling with the two large rubber rings also, after many years they can get hard and draw air.

"Rome wrote:

They use a square[four sided] black rubber 0-ring now instead of the yellow one. I dont have a parts book for the 9's, I'm sure Ole Magnet will have it. The D7E uses a gasket. Thats the suction line for the trans/steering clutch pump.

Rome, thanks of course I have the parts book but can't for the life of me figure that part number as the pictures stink and do not match what I am seeing...Again thanks for always caring enough to take a look....Both coolers are now replaced and do not leak as I drained the engine oil and and of course did not attach the trans/torque cooler until I filled with water the radiator.... No leaks....

Your welcome! Ok, the old number may be a XMXXXX number, the new one should be a 1P#

"Rome wrote:

They use a square[four sided] black rubber 0-ring now instead of the yellow one. I dont have a parts book for the 9's, I'm sure Ole Magnet will have it. The D7E uses a gasket. Thats the suction line for the trans/steering clutch pump. Should be a 1P#. I would replace that coupling with the two large rubber rings also, after many years they can get hard and draw air.

I did get the two new rubber rings for that coupler... I thought I was done but then again never done always something to make right.... You are absolutely correct the old ones are hard as a rock and missing some rubber... Someone at one point had them out and used blue RTV to stop any leaks... The suction side should have some pressure to it but not a lot but still want it not to leak the first time so new rubber all around...

They call the 4 sided square a d ring instead of an o-ring.... The guys at caterpillar told me they dont make a d- ring in yellow... Well you did 50 years ago.... LOL...

Hi George,
the square looking yellow O ring is just that your O ring is old and they take on the shape of the groove after time.
It started life as a yellow O ring that will swell if exposed to solvents--usually soaking in oil restores them after time but they can become easy to tear/break after this.

There were/are D rings in the Cat system but I do not recall ever supplying anything but the yellow O rings in the 9 years I ran the Dealer Trans Bay, of course over time Cat change things and there now may well be a black silicon equivalent of the old yellow O ring.

I believe you need a 6L1649 yellow O ring or its current equivalent and not a D ring.
The said O ring maybe shown in a side view of the Transmission Group where the screens are also shown in cutaway section--it is in the D8H books I have here.

The D8H uses the yellow 6L1649 seal and its dimensions are :- 2.475" ID, 0.210" cross section dia. and as best I recall was the same as the larger D9--I stand to be corrected.
Cheers,
Eddie B.

6L1649 is the correct seal for your s/n. Page 84A-2 in the parts book, item #26.

"Old wrote:

6L1649 is the correct seal for your s/n. Page 84A-2 in the parts book, item #26.

I need a new parts book as mine show the diagram on page 67 but only shows the tube and it is #30. The print out from Cat shows the tube being #28 and the gasket being #26 (6L1649) Thank you as always for confirming and bailing me out.... I really do not like the parts diagram as the illustrations are terrible looks like a kindergarten drawing.... But try not having one.... Oh well... Cross your fingers for me.... Appreciate it again...

"edb" wrote:

Hi George,
the square looking yellow O ring is just that your O ring is old and they take on the shape of the groove after time.
It started life as a yellow O ring that will swell if exposed to solvents--usually soaking in oil restores them after time but they can become easy to tear/break after this.

There were/are D rings in the Cat system but I do not recall ever supplying anything but the yellow O rings in the 9 years I ran the Dealer Trans Bay, of course over time Cat change things and there now may well be a black silicon equivalent of the old yellow O ring.

I believe you need a 6L1649 yellow O ring or its current equivalent and not a D ring.
The said O ring maybe shown in a side view of the Transmission Group where the screens are also shown in cutaway section--it is in the D8H books I have here.

The D8H uses the yellow 6L1649 seal and its dimensions are :- 2.475" ID, 0.210" cross section dia. and as best I recall was the same as the larger D9--I stand to be corrected.
Cheers,
Eddie B.

Hi Eddie,

You have a fantastic memory and one can only hope mine holds.... I am 48 and feel like I loose my brain daily.... I appreciate you taking the time and Old magnet and you are on the same page and believe it or not I was wrong the cat dealer got it right then...Go figure I am eating some crow over this one.... With any luck Beastie will come alive and be happy.... Cheers....George

"edb" wrote:

Hi George,
the square looking yellow O ring is just that your O ring is old and they take on the shape of the groove after time.
It started life as a yellow O ring that will swell if exposed to solvents--usually soaking in oil restores them after time but they can become easy to tear/break after this.

There were/are D rings in the Cat system but I do not recall ever supplying anything but the yellow O rings in the 9 years I ran the Dealer Trans Bay, of course over time Cat change things and there now may well be a black silicon equivalent of the old yellow O ring.

I believe you need a 6L1649 yellow O ring or its current equivalent and not a D ring.
The said O ring maybe shown in a side view of the Transmission Group where the screens are also shown in cutaway section--it is in the D8H books I have here.

The D8H uses the yellow 6L1649 seal and its dimensions are :- 2.475" ID, 0.210" cross section dia. and as best I recall was the same as the larger D9--I stand to be corrected.
Cheers,
Eddie B.

Thought that was odd too, D-ring? the yellow rings were always round.