Torque setting for Cessna Hydraulic pump?

[KJM]

G'Day all.

I have replaced the (profusely) leaking oil seal on the PTO driven pump for my backhoe. It's a (small - because it's on a 16HP Kubota B7100!) Cessna. According to the local agents for Eaton - this is some kind of OEM Cessna and they don't even have parts listed for it They (said) they couldn't even give me torque settings either .

I've replaced the seal, but would like to know what to torque the bolts to! These are 3/8" heads and go into Aluminium. They were TIGHT when I undid them, but the muck-of-ages all over the pump might have made them tight. I don't want to strip the threads in the ally.

Anyone have a clue on the torque needed?

Cheers
/Kevin

 

[Sandlot]

Try these web sites;

Metric Steel Bolt Torques - Engineer's Handbook

SAE Bolt Torque Specs

 

[KJM]

Thanks for that, but I already have those - my problem is that the bolts were tight on removal, and the usual torque figures in those tables and the ones I have (which are the same) are way too low.. Ah well, I'll use my "calibrated arm" and torque 'em up like I found them!

Cheers
/Kevin

 

[Sandlot]

There was probably some type of factory installed thread locker (Locktite) on them. I would follow the chart. I strip stuff using my "calibrated" arm, or what ever I was installing, falls off!

 

[KJM]

There was probably some type of factory installed thread locker (Locktite) on them. I would follow the chart. I strip stuff using my "calibrated" arm, or what ever I was installing, falls off!

I understand where you are coming from - drilled and re-tap'd one size larger too many times already! But there was no thread locker on it - clean, oily threads only. Anyway, the threads are about 1 inch deep into the ally and I've torqued it down evenly. Once I finish moving the tank on the backhoe 65mm back (2.5"), re-locate the oil filter, re-locate the manual hydraulic pump, move the valves back and make some new drop pins for the swing lock - I'll give it a try and see if it leaks!

All this started when I fitted the ROPS - the backhoe and ROPS can't co-exist unless I move the backhoe back. Thought I might as well fix the leak at the same time. You know how it goes... Best laid plans of mice and men...!

/Kevin

 

[slowrev]

Darn Cessna pumps. work fine but finding parts or service for em...My 2444 has 2 of them and at 39 years old they are getting a bit weak.
Does anyone kow of a place that will rebuild Cessna pumps ?

 

[KJM]

Darn Cessna pumps. work fine but finding parts or service for em...My 2444 has 2 of them and at 39 years old they are getting a bit weak.
Does anyone kow of a place that will rebuild Cessna pumps ?

The parts counter bloke said that they all have different part numbers and "similar" looking later model Eaton components won't usually fit. Sigh.

Assuming you have a gear pump - the copper thrusts and bearings can be done by pump shops but the gears might be a problem. Mine has substantial pitting (up to 2mm!!!) on a couple of the teeth - if I were a betting man, I'd bet it had sat in "wet" oil for an extended period. The previous owner seemed to use an angle grinder and welder as his primary maintenance tools

Despite the fairly gnarly looking gears, it still pumps - albeit at a reduced pressure, I think. For me, it'll probably outlive me. Unfortunately in Australia we don't have the equivalent of "Surplus Centre" so buying a cheap replacement seems outlandishly expensive. Given you live in the US, just buying a whole new pump might be cheaper than re-conditioning the gears (which are what I assume are worn). Worth casting your eye over the catalogue - if you know the performance data for the existing pumps, you probably can find a match!

Cheers
/Kevin

 

[john_bud]

Good point, Mate!

Surplus center has pumps -- check them first then get a FIRM FIXED quote to repair and make the smart choice.

 

[KJM]

Good point, Mate!

Surplus center has pumps -- check them first then get a FIRM FIXED quote to repair and make the smart choice.

The reason I suggested it was because of the outrageous prices I was being quoted over the counter from the Eaton agent. These pumps have 2 gears, two copper thrusts and four copper bushes, two case half seals and an oil seal on the input shaft. Pretty simple stuff. He thought they could do the copper bushes for $30 (AUS == $20US(ish)) each. The thrusts he'd order in and couldn't give me a price on (But said it'd be change out of $200..)

So I figure that a new pump - which is 100% all new bits is going to be significantly cheaper going on the Surplus Center pricing. My pump is about 20+ years old, a 39 year old one that hasn't been abused is likely to be in about the same shape - and big $$s to fix, I suspect.

But slowrev - you can just disassemble the thing and have a look. Pretty simple to dismember!

Cheers
/Kevin

 

[slowrev]

I have hit 4 hydraulic repair shops with good reputations so far. And when they hear International and Cessna in the same sentence they just shake their head no.

I have found a nice Barnes pump to replace my front aux pump. $250 vs $800 plus at IH. Exact fit , fittings, flow, pressure, etc

The engine mounted pump is a problem though, just any pump will not fit.....