Komatsu D85-18 Transmission problem

Hi,
I Have a D85p-18 komatsu dozer and when you start it up it will not go into gear initially. If you start it up then let it run for a couple of minutes, turn it off, then start it again it nearly always goes straight into gear. It is very noticeable when the ??transmission pump?? kicks in you can hear the engine change and it will go into gear. the machine will work all day without trouble once it goes into gear

It doesnt seem to matter if the engine is hot or cold. If the dozer sits turned off for more then 10 minutes it will not go into gear straight away. Transmission filters are all clean and no *significant* leaks anywhere.(It is a old machine it has leaks)

Is the pump sucking air?? not Priming??

Has anyone had the same problems. Thanks

Might be a suction leak on the filter housing. Old transmission pumps tend to do that as well. Is it transferring oil into the engine? Sometime is just sticky valves in the transmission. Have you pulled any filters and checked for metal and debris?

The Dash 18 if I recall is fitted with the Cummins NT 855, anyhow if you look under the floor plates you will see 2 pumps fitted to what is a Y style suction pipe, 1 of your pumps is a knacker job and due to the Y setup feed is loosing prime, my thoughts is the Transmission Pump not the steering/ pilot pump. tctractors.
p.s. the filters are pressure filters, there is a suction screen.

Better late then never;
Replaced all seals and o-rings on suction side of tranny and steering pumps, also resealed both pumps. Problem solved, dozer does straight into gear, also seems to drive a lot better, in hindsight tranny oil was bubbly (aerated) and is now back to normal. Thanks for the advice