Cat quick drop valve. 5J3851

[pf/l]

Tidying up a few odds and ends on my D7E and debating which way the quick drop valve went back together. I have a diagram in the service manual. When I took it apart it slid appart a little unexpectedly so I was focusing on not loosing anything. Found one video online but it doesn’t match up with what my service manual shows so just wanted to double check. I tend to believe the manual more then a YouTube video but cat makes mistakes too lol.

Trying to track down replacement seals as well for the lines. Some of them still have the old style metal ring with the rubber inner seal. I had taken them into the one dealer but I believe he gave me the wrong ones. He matched up inner diameters or got close. Now the outer diameter is much smaller of course so there’s nothing to locate it. OD is 2” on the metal ring. He gave me a 1P3704. I believe it should be a 1p3705 but not certain. Have a couple of the crossover lines that are getting chafed so I’m going to replace them while they’re out. In to far now so what’s another couple hundred bucks ehh lol.

 

[heymccall]

 

[pf/l]

Thanks. Appears to be the same as the cat manual. I’m not sure why they didn’t include it in my 173 hydraulic parts book. The cylinders are not included either. They are however in the 173 service manual.

 

[Nige]

I’m not sure why they didn’t include it in my 173 hydraulic parts book.

What's the S/N of your Hydraulic Control.? It appears that 5J-3851 is replaced by 5J-3863 on 65G, 67G, & 48C-prefix 173 controls, and it appears in the parts listing for all three.

Trying to track down replacement seals as well for the lines.

Do you have the Part Numbers of the old 2-piece seals.? Most of them were replaced with the quad Ring (squari-ish section seals 1P37xx) but a P/N of an old seal would go straight to the newer replacement.
EDIT: Alternatively what's the ID of the hose/tube in which they are used.? Note that the hose/tube ID is NOT the ID of the seal.
1P-3703 - 1.0" ID
1P-3704 - 1.25" ID
1P-3705 - 1.5" ID
1P-3708 - 2.0" ID

 

[pf/l]

What's the S/N of your Hydraulic Control.? It appears that 5J-3851 is replaced by 5J-3863 on 65G, 67G, & 48C-prefix 173 controls, and it appears in the parts listing for all three.
Do you have the Part Numbers of the old 2-piece seals.? Most of them were replaced with the quad Ring (squari-ish section) seals 1P37xx but a P/N of an old seal would go straight to the newer replacement.

Unfortunatley I haven’t been able to track down a part number for the old seals None of my books show the valve or lines. My serial number prefix on the tank is 34H. I didn’t realize they were a two piece seal. I never tried to take them apart to be honest.

 

[Nige]

My serial number prefix on the tank is 34H.

Actiually a 173B Control, at least by S/N prefix from the plate on the tank anyway. Gonna need a full S/No to identify it.

I didn’t realize they were a two piece seal. I never tried to take them apart to be honest.

The two-piece seals were cancelled years ago. The replacements are one-piece seals.

 

[pf/l]

Actiually a 173B Control, at least by S/N prefix from the plate on the tank anyway. Gonna need a full S/No to identify it.
The two-piece seals were cancelled years ago. The replacements are one-piece seals.

That’s where the confusion set in a bit in between dealers. One was matching up Id of the old 2 piece seals and the other was matching up the od. I’ll see if I can make out the serial number on the tank again. I don’t have it written down. 173b is correct though I believe.

 

[Nige]

One was matching up Id of the old 2 piece seals and the other was matching up the od

Their first question should have been - "what size bore of tube/hose does this seal fit.?"

I’ll see if I can make out the serial number on the tank again. I don’t have it written down. 173b is correct though I believe.

I would have thought a 173B Control would have been installed from factory on a machine of a much later build than yours. I wonder if the hydraulics on your machine were an afterthought (not all tractors were built with hydraulics) and has been cobbled up from a mish-mash of parts originally installed on other machines.?

 

[pf/l]

34H2574 is the full serial number.

 

[Nige]

34H2574 is the full serial number.

Probably right. From what I can see 48A tractor production started in 1961, 34H 173B/183B Controls started in 1965. I didn't realize there were B-series controls out that early, I thought they were 1970s iron.

I may have found the missing link regarding the QD valve. On a lot of mid-size models it's part of the Dozer blade Parts Manual. This is logical when you consider that the QD valve is mounted on top of the blade lift cylinders which are also found in the Parts Manual for the blade. If you have a S/N on your blade then that would be the next point to start.

 

[Nige]

Just as an example...........

 

[Bluox]

Unfortunatley I haven’t been able to track down a part number for the old seals None of my books show the valve or lines. My serial number prefix on the tank is 34H. I didn’t realize they were a two piece seal. I never tried to take them apart to be honest.

Those seals are called a metal back seal they are not 2 piece seals.
The replacement seals are a D-ring seal not a quad seal.
The good news is no one reuses those fittings, and the new hoses will use an O-ring.
You now see the importance of using the serial number for part searches.
Bob

 

[pf/l]

Thanks everyone. Greatly appreciated as always. I took the steel line assembly in off the cylinder along with the old hoses and both my supplier and I agreed that the 1P3705 should be the correct one. Got new hoses made up. Code 61 fittings. Believe I have everything I need now. Those flange fittings were expensive to say the least though. 50$ each. Two hoses and a new flange kit cost just shy of 400$ cdn. Was going to go to cat but they only had 3 of the straight fittings. Luckily the other specialty shop stocked some d rings.

 

[pf/l]

Probably right. From what I can see 48A tractor production started in 1961, 34H 173B/183B Controls started in 1965. I didn't realize there were B-series controls out that early, I thought they were 1970s iron.

I may have found the missing link regarding the QD valve. On a lot of mid-size models it's part of the Dozer blade Parts Manual. This is logical when you consider that the QD valve is mounted on top of the blade lift cylinders which are also found in the Parts Manual for the blade. If you have a S/N on your blade then that would be the next point to start.

That would explain the mystery alright. Thanks Nige. I have no idea what the serial number might be on the blade unfortunately. I’ve never really thought to look for a parts book as in my mind there wasn’t really much to replace. Will keep my eyes out now though and see what’s out there.

 

[56wrench]

The s/n of the blade should be stamped on the rh upper backside of the blade if i remember correctly. You may need a wire brush to find it

 

[pf/l]

The s/n of the blade should be stamped on the rh upper backside of the blade if i remember correctly. You may need a wire brush to find it

Thanks I’ll take a look and see if I can find it. One thing I suspect though is the blade and c frame may be off of a older D7. It’s a angle blade but it doesn’t have the square push arms on the angle arms. They are round like some of the older ones.

 

[Nige]

This is approximately where the S/N plate should be on a 7A blade. Seems as though all the blades share the same illustration with only part number differences between on S/N prefix and another. If there is no plate there look for the two screw holes to give you an indication.

 

[Nige]

I would guess you might be looking for something like this ................ https://www.ebay.com/itm/3719475006...55-0&campid=5338722076&customid=&toolid=10050

 

[pf/l]

I checked the blade over fairly carefully tonight on my way home. Definitely no tag left and couldn’t find any stamped numbers unfortunately.

thanks Nige that’s kind of what I was thinking too. Surprisingly quite a few of them on eBay. I was browsing through last night and found a few for around that 35-40$ range. Pribably worthwhile having just for the hydraulic parts if nothing else. I always wondered why I couldn’t find those diagrams and now I know. Thanks.

 

[pf/l]

Guy who made my hoses screwed up somehow and made the one about 4 inches longer then the other. I had asked for a extra inch but not 4. Thankfully long enough it can be cut and a new end crimped on. Measured the distance between the flanges so I can get a more exact fit as well. Hopefully they’ll help with the cost some at least. If they had made it the extra inch long it would’ve been bulging a bit anyways. Original was about 6 inches longer but it seemed to be a more flexible hose. The excess didn’t end up in the fan like the new one.(the last thing I need after doing all that work) I swear everything I’ve done on this project has had a complication of some sort lol.