1989 d4h

[1989d4h]

hey folks I bought a little 1989 d4h cat recently and am having trouble with a light on the dash flashing and alarm buzzing it appears to be the trans fluid level light (so I believe)... the oil is right where it should be on the dipstick hot and cold temp.. filters have been changed (not cat brand filters) screen is clean of debris. trans temp runs around 200F and everything operates normally no problems shifting I do not want to run the machine until I figure out what the problem could be incase there is a problem somewhere along the line . it could be a faulty sensor?
any information will be much appreciated thanks
steve :Banghead

 

[1989d4h]

forgot to mention that machine dosent have to be running for light and buzzer to come on as soon as I turn the key on it starts flashing and buzzing

 

[Nige]

There are 6 warning lights in two columns of three. If the warning light to which you refer is the top one in the RH column then it is a warning for transmission oil temperature, not level. If it is the bottom RH light then it is for a plugged transmission filter. The high temperature warning will only light the warning light, the plugged filter warning will light the light and sound the buzzer. I suspect from your description that your warning is most likely the plugged filter warning although how it can sound even before starting the engine is strange, more commonly it will sound once the engine is started, especially with could oil.

From your description of the problem It would appear that you most likely have either a wiring fault, a transmission filter switch fault, or maybe a stuck spool inside the transmission filter head that activates the switch.

Both the power train temperature sender and the switch should be pretty close together, at least one of them ought to be located on the transmission filter itself. How to tell the difference between them is that the temperature sender only has one wire connected to it, the filter switch has two. Try removing the switch from the filter then reconnect it to the machine wiring and turn the key on. Does the alarm still sound..?

A machine Serial Number would be helpful to locate the correct Electrical Schematic for your machine. There are about 10 different models of D4H.

 

[1989d4h]

hey sorry it took me so long to get back to you im back from out of town now I will go get a new filter today and clean up wireing conections n hopefully that gets it back to normal, it is the light on the bottom right column, thanks so much for the information glad theres people like you out there !

heres what the badge says, D4H *8PB02360*8Y0520

3204DI *45V69890*1N8608

*1CE03072* 8T8315


any other information you can tell me about the machine is always appreciated :notworthy
thanks very much
steve

 

[1989d4h]

got a new filter and 6 pails all cat brand stuff worked good for a half hour then light and buzzer came back on tomorrow ill go get a new sensor ... what is a normal trans operating temp?

 

[Multiracer]

Make sure you remove all components of the filter switch. I found an old o-ring from the top of the filter housing wrapped around mine. There is also a bulletin out about the super high efficiency filters not being used in transmissions any longer.
Stick with what Nige recommends, he has helped me numerous times with my 1988 D6H.
Ron

 

[Nige]

What part number of filter did they sell you..?

 

[Nige]

Another thought after Ron posted above. There doesn't appear to be anything wrong with the plugged filter switch if the machine ran for 30 minutes before the alarm went off . Either the new filter is plugging (with what?) or the bypass spool that operates the switch that causes the alarm to go off is moving when it shouldn't. That would most likely be a broken or tired spring, or bits of old o-ring from previous filter changes like Ron had. Really the only way is to disassemble the bypass valve completely and make sure it's clean. That way you'll know what you have.

 

[kshansen]

I know this is a bit off from a D4H but we had a problem similar to this with a 988H. Warning indicator for plugged filter was coming on somewhat random and always with oil warm. I had checked the switch in filter head and felt it was in good condition, boss said put a new one in to be sure. Well it still would light the indicator and sound alarm sometimes only once a week for a couple minutes. As grounding the wire to the indicator keeps the warning alarm and light off, open circut turns it on, I started to narrow down the problem by installing a temporary ground to the wire starting at the oil filter. I then moved along the harness at each junction I could easily access along the way and each time after a period of time, often days, the warning would come back. I got to the point where I had a 3 inch wire from the module grounded to the cab frame. It still would trigger the alarm on occasion. After talking to the Cat dealer techline was told problem must be in the monitor module it's self! As this module is not cheap, I believe around $700 hesitated to jump right on buying a new one and was trying to locate another machine I could "borrow" one from to test this theory with. Just by chance while doing some service work on the machine with the key on but motor off looked in the cab and the saw the warning light was on! For a change I did have someone who could help me by watching the light while I wiggled the wiring near where I had been working. That's when I found that touching the wires connected to the temperature switch on top of the transmission control valve would turn the warning light on and off. Ordered and installed new temperature sensor and the "filter plugged" indicator problem went away. Never was able to get anyone at Cat to tell me why a bad temp sensor was triggering a "Plugged Filter" warning.

 

[Multiracer]

If Nige can help you with a schematic there is also a temp sensor tied into the plugged filter warning.... I can not remember what but there are two sensors on the trans, one is for the gauge and one is a 125 degree sensor.... but it escapes me what that one was for.

 

[Nige]

I'm away from home at the moment Ron. It'll have to wait until I get back.

 

[Multiracer]

I did not mean to volunteer you for this.
Enjoy the time away while you are away

 

[1989d4h]

hey thanks everyone for the help I took sensor off housing and hoked wires back up n pressed it in with my finger and light went out so sensor is good ... so I fingerd the plunger in the housing and she poped out! it was just hung up in there a bit so problem solved for now all is good and we back to normal thanks again for all the help

steve

 

[Multiracer]

That is good inexpensive news. I would still pull the plunger and look over the spring, the plunger and the bore. It is all very tight tolerances but a bit of fitting and it all goes back together rather easily.
Good luck

 

[cfisher05]

I’m having same issue 1989d4h, or anyone else, can u give me a little more detail where the plunger and spring are, I changed the filter and I didn’t see anything in with the filter, but I may have missed something
Replaced filter after pushing dirt light comes on leave sit light goes out until start pushing again , approximately 10-15 mins pushing but will just sit and idle for 30-40mins or better and never come on

 

[Nige]

You're asking a question on a thread that has been dormant since 2015. Your best bet IMO is to create a new thread describing your symptoms and at the very least quoting a machine Serial Number. That would enable the appropriate parts diagrams to be located.