Cat 315 bl. Tracking issues

[Dozier Digging]

I have a cat 315 bl With 8900 hrs I just rebuilt the swivel and I'm still having a issue with turning the the machine it goes straight ok but feels lazy but when you pull the levers to turn it just sits there unless you use the boom to help the turns ok I noticed my 2 speed button doesn't work I was thinking it may be in high but it travels slow . any advice

 

[Nige]

I think if it was mine I would diagnose and fix the 2-speed issue and then go from there. IMO it's no use trying to diagnose a fault when you have another known issue muddying the waters so to speak.

 

[John C.]

When you get done with Nige's suggestion I would suggest doing some cycle times on the boom up function and letting us know what you get.

 

[Dozier Digging]

I have search the machine over and I cant find the 2 speed solenoid any ideas where this is located

 

[Nige]

The system on the 315BL is not a true 2-speed system. This is what the manual says about it...... Travel speed switch (56) provides selection of HIGH or LOW travel speed. When the switch is placed in the SLOW "TORTOISE" position, the machine travels at the LOW speed mode. When the switch is placed in the FAST "RABBIT" position, the machine travels at the HIGH speed mode. On a flat surface or moderate downward slope, select the HIGH speed for increased mobility.

While travel speed switch (56) is in HIGH TRAVEL SPEED MODE position, pressure sensor (43) operates to automatically change the travel speed depending on the load placed on the machine. The machine travels at LOW speed when a larger load is placed on it and travels at HIGH speed when a smaller load is placed.

The pressure sensor (43) referred to above is in the pump compartment, the travel speed solenoid valve (45) is in the pilot oil manifold compartment. See below.

 

[lantraxco]

So it's like your car automatic transmission then, you can lock it in low, but in high it decides if you get high or low depending on how hard it's pulling?

 

[Nige]

I've wondering if the pressure sensor (43) signal that destrokes the pump above a certain load when in HIGH speed mode could be on the fritz. Surely the default position would be LOW speed travel if no sensor signal was received..?

 

[lantraxco]

I've wondering if the pressure sensor (43) signal that destrokes the pump above a certain load when in HIGH speed mode could be on the fritz. Surely the default position would be LOW speed travel if no sensor signal was received..?

One would hope so.....

 

[Dozier Digging]

Ok thanks I will check these out tomorrow I just completely serviced the machine including hydraulic filters I ran it for a couples hours yesterday loading some dirt I had stock piled it pulls better forward than reverse hydraulics seem strong it pull the bucket thru the ground but a couple times it bogged the engine way down like almost killed it I have a small drip oil leak on the pump one of the end cap seals I believe is leaking I was just wondering if I'm losing pump pressure with this leak could that be my problem but at the hrs it has it may need the pump built

 

[lantraxco]

Probably should do a complete hydraulic check and adjust, not sure what all that entails on that machine. Typically it's check and set the pumps, main reliefs, then all the individual port reliefs, the drive motor case drain flows. Then cycle times on everything. Sounds to me like you have some internal bypassing, either port relief valves or cylinder seals, when you get excess flow at pressure that will drag the engine down, or if the pumps are not destroking correctly under heavy load.

 

[Dozier Digging]

1 thing I forgot to mention that when traveling on flat ground at full if you move the boom ,bucket,stick etcit will pull the engine down some and slow the machine down

 

[w2bstoned]

Mine does the same thing... Gotta remember it's old cat now nothing like the new ones

 

[big ben]

1 thing I forgot to mention that when traveling on flat ground at full if you move the boom ,bucket,stick etcit will pull the engine down some and slow the machine down

Unless its really pulling the engine down this is normal. You are putting all your flow to travel and then if you move another function generally your travel speed get cut in half cause now the pump is sending oil to functions other than just travel. And as others have said - it the machine doesn't know the pump pressure (bad sensor, wiring etc) 2 speed will not work

 

[Dozier Digging]

Ok I had to set this machine aside till I could work on it so I had some time ended up replacing the prv valve now the machine doesn't bog hardly at all but still still not tracking good and still will not change speed when you go from turtle to rabbit it shows it changing on the monitor but don't actually change speeds

 

[Dozier Digging]

The more I look at this forum I see a lot of cat 315 with issues

 

[norite]

The more I look at this forum I see a lot of cat 315 with issues

Maybe there are a lot of Cat 315's out there.

 

[Dozier Digging]

There are alot out there only problem I seem to have is noone around me knows how to work on them any heavy equipment mechanic I ask tells me to take it to the dealer

 

[Dozier Digging]

So after I installed the prv valve 2 days later it goes back to bogging