Leaky backhoe hoses

Greatwideopen · Mar 9, 2011

My dad's Kubota L35 backhoe has a leak in 1 or 2 of the 6 hoses leading to the backhoe. I can' see for sure, but it drips off the bottom where the main boom attaches near the ground. Leaking inside the steel tube. Can anyone help me with how best to replace the leaky hoses? Where all the hoses go past the main cylinder connection from the valves is VERY tight. Even where the hoses come out of the boom to feed the upper cylinders is so narrow and tight I'm not sure how to get a new hose through. Do I pull the pin on the main cylinder to make room? I would like to do the repair myself but have little experience with it.
Ay thoughts are greatly appreciated!

Joe

J_J · Mar 9, 2011

In a tight situation like that, and if I had to replace a hose, I would just couple the new hose to the old hose and pull the old out and the new hose should slide in between the other hose. You might try some liquid soap for lube. I had about ten hoses in a small tunnel on my machine, and it worked for me.

TracTrac · Mar 9, 2011

Good advice J_J.
Just be very care to not allow any dirt or grit to enter the hydraulic system. Any hydraulic systems life will be cut short by contaminants.

JerryG · Mar 9, 2011

Tie a heavy string /cord on the old hose. Pull the old hose out with the string /cord behind it. Then use the string / cord to pull the new hose into place.

David-Davies · Mar 10, 2011

Hello JerryG. Your sugestion is good, but, if your pulling a hose through a tight hole, the hose will bend were it is ties to the string, so will be a little bent, making it hard to pull through a tight spot. Secondly, it will let dirt in the hose, unless you tape the end closed, then hope that the tape stays on. As J-J said, use the old hose to pull the new hose.
Dave

Cantoo · Mar 11, 2011

I have an L35 and have replaced 2 hoses on the boom already. I cut the protective sleeve in the middle and pulled it back over the hoses. There is enough room to get the new hose in easily enough. The hard part is finding which hose is leaking, they will all be covered with oil so sliding a new one in is easy. Keep in mind you are disconnecting the hoses so make sure the boom is supported from falling down. Also might have to grind abit off of your wrench to get the fitting tight, little tough to get them to turn tight.

Greatwideopen · Mar 12, 2011

Thanks for the good advice. I wound up replacing three of the six hoses today. I took the pin out on the main boom cylinder to free up some room to route the hoses and all went well...except....

The dipperstick cylinder is barely moving now. The main boom cylinder works fine. Both had a new hose put on today. I assume the dipperstick cylinder may be air locked? I was very careful to keep everything clean - I covered every hose end with a zip tied cloth.

I've tried cycling The cylinder a number of times but no luck. Do I need to bleed something?

Any advice is appreciated.

wdchyd · Mar 12, 2011

Greatwideopen,

Curious, was the replacement hoses "Gates" brand 1/4" (#4 ) hose..??

Possibly one or more hose ends could have been overcrimped.....I've seen this before...the 1/4" size is vulnerable to this cuz it's already a very small orifice before crimping......

Pics ..??

Greatwideopen · Mar 12, 2011

Yes, they were gates hoses, but two were 3/8 inch and one was 1/2 inch all with 1/2 inch fittings. How would I know if there was a blockage? I thought it was likely air, but the truth is I know little to nothing about hydraulics - not even sure if air in the line can cause a problem.

wdchyd · Mar 12, 2011

Air wouldn't cause this....the air would work it's way out aftr several cycling of cyls.....

I'd pull off the ends of all the hoses that connect to the suspect cyl.....then find a set of punches of different sizes( L.S. Starrett 52586 Drive Pin Punch Set W/BOX 8 pc slide them in the crimped ends to compare internally......a flashlight visual inspection may work also.....

The problem with Gates hoses is the crimper has digital stop switch which must be properly set, if set wrong or out of calibration it could crimp too tight (seen it before)....

other brands of hose have crimp dies that are directly matched to the size/type of hose so that the crimper just presses and bottoms out to complete the crimp.......

The Gates crimper is not as user friendly and can be set wrong......or someone set it properly and just used the wrong dies......

For sure check these closely and if you can't visually check then use the punch/tool method.......

Pics would be nice ..!!