My CAT 301.8 mini excavator does not have full drive power to the RHS track. The LHS seems normal. The RHS goes much slower and has less power. Anybody got any ideas where to start looking for a problem?
If you track and for example swing at the same time is it weak then also? Something that is common on these is that one or more sections in the pump gets worn but in that case you should notice that the stick is weaker as well since that is fed by the same section. Get hold of a manometer and check the pressures, there's test ports on the pump outlets.
Thanks Per. The stick is also slow moving, so good call there. There is only two pumps on the machine and I have done a seal kit on one before. That time a piece if o-ring had broken out. Maybe same is happening again. If not, what other things cause this? Oil is obviously not going where it should I suppose.
OK - I have pulled the pump down and found the seal has failed again in nearly exactly the same way as last time. I am wondering whether the plates that go against these seals need some sort of "facing" to take out the inevitable wear marks. Anybody know what is best practice here.
There is a plate in the middle of the pump - I am almost pointing to it in the next photo. The one about finger-width in the middle.
Perhaps check so the parts involved are flat and not warped. How does the gears look, any wear marks?
Turns out that where the o-ring and plastic retainer are broken in the photo thatbthe aluminum body of the wear plate looks to have been machined wrongly/badly from day 1. The hydraulics bloke I took it to today had never seen one fail like that and his co-worker said it is a machining fault. So I am going to put it to CAT for a replacement. A new pump is $1020 in Australia. Part number is 159-7181 for machine serial number BFA00973. Wonder how much that is in the USA.
Price in US: $882.48, but it said to contact dealer on avaliablity.
Maybe i'm having a similar issue, both of my tracks are pretty weak. and i've noticed some of the functions are slow.
It's pretty quick to pull the pump off and open it up and take a look. The one that drives straight off the flywheel.
My pump is different then the one in your picture pete, It has 3 ports coming off not just two. I'm guessing after a quick look at mine you pull the fittings then take of the two bolts that hold it on. Then to break it apart your take out the 4 long ones that run through it. Does that sound right?
Correct. I pulled the battery and the battery tray out for easier access to the pump. When you pull it apart just take a good look at the way it goes together, noting the oil inlet side and the outlet side. There are a heap of O-rings and retainers in there. That seal kit cost me $132 here in Australia.
Whats the reason for the extra port on mine?
Don't know.
does yours have auxilary hydraulics?
Hydraulic pump seals gone Hi Pete, Have a fiend in NZ and his seals have gone. Can you tell me where in Aus you bought the seal kit. The pump is Cat 201-0920 10/3 940120/001-75 on his Cat 301.8. In NZ Goughs say must buy a new pump around $1700NZ? any help appreciated. Thanks Tam
Hi Everyone, If you are looking for the seal kit for the gearpump Casappa has them part number 62046718. I just spent about 2 weeks researching this because in Canada they want 1800$ for a new pump and won't sell the seal kit and the only thing wrong with the one I have was a small leak. Casappa actually doesn't sell to just any Joe Blow so I actually ended up going to Cannamex and there you will need to use part number 189625 about 100$ CAD. This was actually one of the first forums I stumbled upon in my research and when I saw no one answered Pepe I was upset. So hope this helps someone in the future. Oh almost forgot: The model is PLP 20 3 pumps with center common inlet. Drive shaft: SAE Spline 07 Mounting Flange: SAE "A" 2 bolts S9 Common inlet version S7 These are Casappa part numbers of Thrust Plate Seal: 39656100, you will need to order [6] Anti-Extrusion Ring: 41387100, you will need to order [6] Housing Seal: 39666200 , you will need to order [6]
Hello everyone, seems like I'm having the same problem with my 301.8c, the only thing is my pump is different. My pump is a variable displacement with dual gear pumps attached part# 241-7971 On one side of the main pump I'm getting 3300 psi and 1200 on the other, both sides are supposed to be equal as I have tested it when it was working good .
What is the Serial Number of the machine.?
Outlets P1 & P2 are for main hydraulic system, P3 is for Swing, P4 is for Pilot system. Try the attached test procedure and post the results.
I did the hydraulic pressure test, I'm getting 2700 psi on P1 and 1200 psi on P2 What i did then is switch P1 and P2 hoses and the problem switch, for instance the boom was fast an stick slow, now the stick is fast an boom slow. I also replaced the hydraulic pump with a brand new pump and all filters, cleaned metal strainer in hydraulic tank.
If you only got 1200psi on P2 did you try the adjustment procedure (it starts at the bottom of Page 7 of RENR9155) to see whether or not the pressure reading increased.? The only thing I would suggest is that you take careful note of the position of the adjuster before you start messing with it so that in the event that it does not produce the desired result you can easily put it back exactly where it was before you started.