Hi, gvanhouten.
I am very pleased for you that she got up and moved for you with no further issues. They were and are one tough machine. Cat have made a few duds over the years, although less, I think, than pretty much any other name in the game, but I also think that the D9Gs, especially the later ones, were and are one of their brighter stars.

As Gauntjoh said, you have pretty much repaid for all the help you received here by joining ACMOC and taking a whole bunch of people on your journey with you 'cos, in the process, you have surfaced a LOTTT of knowledge and a LOTTT of ideas that will have been seen by far more people than just those who have posted in this discussion. THAT is what this BB is all about.

Re the headline of this post and as mentioned previously, we have a show coming up at Santa Margarita Ranch, Santa Margarita, CA, on Memorial Day Weekend, May 22 to 24, 2020. If you can make it here, I would be honored to shake your hand and buy you lunch.

And just so that I not seen as being biased, there is another show at another venue - although likely with a lot of the same suspects - at the Tulare Agricenter, April 17 to 19.

Both of these shows will have working displays, grand parades, etc., but the ranch one also has military hardware and warbirds, the old Disneyland steam trains running and a commeorative service at midday each of the 3 days with the warbirds doing a flypast during the service.

I suspect that there will be a fair bit more publicity on here for both before the respective events. You would also likely be able to meet a few more of the people who have posted in and/or followed your journey.

Just my 0.02.

firstly, Congrats on getting the old girl up and running and driving. your perseverance and patience has paid off.

after reading your last post, just curious if anyone can shed light on the oil pressure safety you find in the governor? Would this impact the fuel delivery problem you were experiencing when you were trying to bleed the #1 injector? i can't see the engine oil pump creating that much pressure while cranking, all of my electric start engines that have the old style bordon tube oil pressure gauges don't register pressure until after the engine catches and begins to run.

how did they engineer the governor to have a shutdown related to oil pressure that didn't prevent the engine from delivering fuel for a start up condition? is it because the spring pressure of the governor is pulling the rack to full fuel until the weights start spinning and move the rack back to the desired engine speed as set by the control linkage?

The oil pressure control is part of the decelerator function.

"rmyram" wrote:

firstly, Congrats on getting the old girl up and running and driving. your perseverance and patience has paid off.

after reading your last post, just curious if anyone can shed light on the oil pressure safety you find in the governor? Would this impact the fuel delivery problem you were experiencing when you were trying to bleed the #1 injector? i can't see the engine oil pump creating that much pressure while cranking, all of my electric start engines that have the old style bordon tube oil pressure gauges don't register pressure until after the engine catches and begins to run.

how did they engineer the governor to have a shutdown related to oil pressure that didn't prevent the engine from delivering fuel for a start up condition? is it because the spring pressure of the governor is pulling the rack to full fuel until the weights start spinning and move the rack back to the desired engine speed as set by the control linkage?

I believe you are very close with your idea... From what I can figure out is the rack gives enough fuel to initially start the beast then in order to go to idle there is a rod or pin in the top of the governor that when oil pressure is good it forces the rod down to allow the rack to fuel up. Of course there is a spring with a certain pressure that is equal to proper oil pressure.... Once I got the oil level on idle filled we where golden.... yes the mechanical engineering for the D9G is not as simple as one would think for 1970 engineering... pretty advanced in you think about it.

"Deas wrote:

Hi, gvanhouten.
I am very pleased for you that she got up and moved for you with no further issues. They were and are one tough machine. Cat have made a few duds over the years, although less, I think, than pretty much any other name in the game, but I also think that the D9Gs, especially the later ones, were and are one of their brighter stars.

As Gauntjoh said, you have pretty much repaid for all the help you received here by joining ACMOC and taking a whole bunch of people on your journey with you 'cos, in the process, you have surfaced a LOTTT of knowledge and a LOTTT of ideas that will have been seen by far more people than just those who have posted in this discussion. THAT is what this BB is all about.

Re the headline of this post and as mentioned previously, we have a show coming up at Santa Margarita Ranch, Santa Margarita, CA, on Memorial Day Weekend, May 22 to 24, 2020. If you can make it here, I would be honored to shake your hand and buy you lunch.


And just so that I not seen as being biased, there is another show at another venue - although likely with a lot of the same suspects - at the Tulare Agricenter, April 17 to 19.

Both of these shows will have working displays, grand parades, etc., but the ranch one also has military hardware and warbirds, the old Disneyland steam trains running and a commeorative service at midday each of the 3 days with the warbirds doing a flypast during the service.

I suspect that there will be a fair bit more publicity on here for both before the respective events. You would also likely be able to meet a few more of the people who have posted in and/or followed your journey.

Just my 0.02.

Des, again not enough thank you’s to go around here. I will be at the California show and I will be buying lunch and shaking hands... I am looking forward to it!

"Old wrote:

The oil pressure control is part of the decelerator function.

Thanks for the diagram and explanation OM. That relates perfectly to the symptoms George explained.

"Dizzel" wrote:

Thanks for the diagram and explanation OM. That relates perfectly to the symptoms George explained.

I didn't think that was a problem until (if I interpret right) George indicated the engine was low on oil. Hard to believe that was allowed after all the effort and still put the engine at risk.

"Neil" wrote:

Good job George. What are your thoughts on what factor(s) enabled it to start and run? Based on what you wrote, I'm heavily in favor of the extra oil in the cylinders providing a better compression ratio to increase temperatures. How much do you estimate you inserted per cylinder?

I am not sure it was ever really compression.... I put a ton of Risilone down the glow plug holes on top of the piston... I did all 6. I did it probably 5 or more times since I have owner her... I put some mystery oil down as well and let it soak... It was with the assumption that the rings where stuck... Based on what I know and it is hard to say but I though that possibly only 2 cylinders would have stuck rings on the piston... But not knowing which ones because I never did a compression test to outline which ones where or are effected...

I really think I had multiple air leaks in the fuel system... That would be a major factor... The more I took apart the more I was chasing my tail... Of course at first I think the timing was the major issue after I took the IP off.... But looking back I would do it again but only one time not three....

The old owner can't believe it starts up so easily now.... It never has started so fast and consistent.... The previous owner was a high end contractor and never really put a ton of money back into his equipment except when it broke and I would say the majority of repairs where not done properly and where just to get the job done... Never to make her right... my goal is to make her right and start properly and we have that now.... I really think there was a multitude of factors that caused her not to start.... Mostly fuel side... as that is what I replaced the most of...

The oil on this old girl is vital and must be maintained to keep her running perfectly.... I will continue to monitor her fluid levels and like I said I have some more to do to her before I put her out to work... I just want her home where she gets a bath, some new paint, of course new parts that she needs.... I know the ripper cylinders have some leaks so I need to repack the cylinders... A lot of people just add hydraulic fluid... I can't stand that fix the damn leak... On my D7g I replaced both cylinders packing and with the right equipment its pretty easy....


I need some suggestions for a pipe for her exhaust... Straight pipe thinking stainless with a flapper of course or maybe a straight black pipe with a bend. Need to know where to buy it as caterpillar is crazy on that price.....along with most other stuff.... Let me know your thoughts...

"Neil" wrote:

Good job George. What are your thoughts on what factor(s) enabled it to start and run? Based on what you wrote, I'm heavily in favor of the extra oil in the cylinders providing a better compression ratio to increase temperatures. How much do you estimate you inserted per cylinder?

I just re-read my answer to you and didn't like it... First I did add some Lucas super thick oil awhile back. Didn't really do much as far as huffing and puffing... When I added Risilone and had her timed right big black smoke came out and she started to really huff... I believe this was the safest way to lube the cylinder walls and it had a high flash point... So I would say despite the air leaks in the fuel system it hit it off... The Risilone guaranteed is the way she lit off not the oil... After she started the oil was low and would not idle... No harm came to the engine as it just would stall not because of overheat or lack of lubrication but the governor literally shuts down the engine....

So really Neil it was the Risilone that made her come back to life... It does not appear to be a lot of blow by so the rings either because of Risilone reset themselves or also cleaned up the cylinder walls.... I hope this answers your question... The one last thing is having it timed correctly the IP lifters set perfectly and all new parts make for the D9G to run like a top....

I did abuse the hell out of my new starter, So after 3 tries with the Risilone it heated the cylinders and burned as well.... I would say viscosity is minimal like 5 or less.... I would recommend doing what I did in the future for someone else... But you have to be super careful not to hydro lock her....Ok so in closing when she finally lit off was after cranking that starter for almost a straight minute with fully charge batteries and each cylinder kept coming on line and the starter was just helping it pick up more speed as they came on line.... Needless to say when she started I think I was in shock and to be honest still am to this day.... I can't believe she is out of the pit and into the sun... She is due to come home this week....The family is going up now to take some pictures on her. My life will get back to normal now.... A big relief is off my shoulders for now... Prior I was thinking how to recover her and the cost associated with that... We would be looking at $10,000 to recover her from where she was and that is if even someone would attempt to do it....