[How-To] Hydraulic plumbing: how do I stop this from leaking?

[ErichKeane]

So I recently got a hydraulic shaper and I'm trying to get it back to tip top shape. I noticed it is taking a bit to build up pressure, so I pulled the side off and noticed it is leaking quite a bit at the angle coming out of the block here(top left):

This required quite a bit of careful disassembly to get out, but I eventually did. It says cat40 on the side of these pipes.

Getting this back together is likely going to be a bear, so I was hoping someone could give some advice. The biggest problem is that I have to install the "near" 90 alone, overtighten it (so there is clearance to tighten the straight/other 90), then "loosen" the 1st 90 to get the pipes lined up right.

I presume this is why it was leaking as much as it was at that junction.

So I guess my questions are:
1: is there a trick to doing this? Is there some expanding, slow drying goop you put on the pipe threads that wouldn't let it leak?

2: could I be better to replace them with a different type of fitting? Perhaps a flexible hose of some sort? I have a pipe thread on both sides ( see the balck pipe on the other hose), but perhaps I could use AN fittings and some braided line for this instead?

Any other thoughts to make this an easier assembly?

 

[FOMOGO]

I would just clean them well, apply teflon tap (at least 3 wraps), then teflon paste making sure to apply in the same direction as the tape. You could change to hose or other fittings, but it would be a lot of expense for something you will probably never have to service again. pretty common to have to back off fittings a little in tight areas. I wouldn't go to crazy tightening. this is probably a fairly low pressure system. Mike

 

[ErichKeane]

I would just clean them well, apply teflon tap (at least 3 wraps), then teflon paste making sure to apply in the same direction as the tape. You could change to hose or other fittings, but it would be a lot of expense for something you will probably never have to service again. pretty common to have to back off fittings a little in tight areas. I wouldn't go to crazy tightening. this is probably a fairly low pressure system. Mike

According to the manual, it is 800-1000 PSI!

I think perhaps the Teflon late is the magic goo I was hoping existed.

 

[FOMOGO]

That is a comparatively low pressure. Mike

 

[ddillman]

use Teflon paste for hydraulic fittings not tape. there is also a nut with a rubber seal that you can use with on the male pipe fitting to help seal it. I don't remember what they are called

 

[ddillman]

look up NPTF thread nut

 

[mmcmdl]

Most flex hose is rated at 3000 or 5000 psi .

 

[Larry$]

I'm no hydraulics expert, but if I was doing it, I'd just use Teflon thread tape. It is quite heat resistant and slick enough, to make changing the thread insertion depth by a little, a non-issue. Teflon tape also allows easy removal later if needed. Check with a hydraulic manufacturer about the ideal sealant.
I've worked on a lot of heavy equipment, modern hoses are quite good but getting them installed in tight spaces isn't fun. They are quite stiff. Often they are screwed into steel blocks with an O ring grove and that is bolted over the port.

 

[ErichKeane]

use Teflon paste for hydraulic fittings not tape. there is also a nut with a rubber seal that you can use with on the male pipe fitting to help seal it. I don't remember what they are called

I'll do that! The NPT sealing-nuts look like they might be quite useful! I'm hoping the teflon paste you mention will fix my problems

Most flex hose is rated at 3000 or 5000 psi .

Well, huh! I've not really worked with hydraulics before, so pressures like that are crazy to me!

I'm no hydraulics expert, but if I was doing it, I'd just use Teflon thread tape. It is quite heat resistant and slick enough, to make changing the thread insertion depth by a little, a non-issue. Teflon tape also allows easy removal later if needed. Check with a hydraulic manufacturer about the ideal sealant.
I've worked on a lot of heavy equipment, modern hoses are quite good but getting them installed in tight spaces isn't fun. They are quite stiff. Often they are screwed into steel blocks with an O ring grove and that is bolted over the port.

That is good to know about the hoses! I was really thinking doing the 90 degree corner (the angle off the block down to the part it screws into) would end up simplifying reassembly, particularly all the funny-business I had to do to get it all loosened (a crazy series of wrenches/punches to turn it about 1/8 turn at a time) but if that isn't the case, perhaps I just need to fight it a bit more.

Thanks!

 

[mmcmdl]

Working with hydraulics is a major PITA . You need bent wrenches , multi angled wrenches , cut off wrenches etc . They're never in an accessable area either . I used hydraulic oil for shampoo for 4 years down at Sunpapers working on their presses .