Volvo EC15B Hydraulic Relief Adjustment

[jackpreacher]

My Volvo EC15B has just had its engine rebuilt and is running fine. see this thread.

The hydraulics were a little weak, namely the travel motors and digging power [well, that's pretty much everything!] so this thread is how I adjusted them.

Firstly a scan from the service manual:

Hydraulic Relief settings.jpg

TBC

[jackpreacher]

Procedure for setting the Relief valve to 170 Bar +/-5 bar

Test kit.jpg
This is the test kit that Muz recommended in my original thread

remove battery compartment cover.jpg
Firstly, remove the cover that hides the battery and fuses. This is just 2 bolts on a 12mm socket.

remove the floor psn.jpg
Next, lift the floor out. There may be 4 bolts holding the floor down but mine didn't have them....maybe they don't exist

remove hydraulic service panel.jpg
Un bolt the hydraulic cover on the 'nearside' of the cab - just 4 hex bolts.

locate the Pressure test point.jpg
Locate the pressure test point - see the first scanned picture from the manual - I had to replace mine with one from the test kit as the fittings were not compatible.

connect pressure test gauge.jpg
Clean up the area where you are working and then connect the flexible pipe from the kit. It only has to be finger tight.



place gauge safely away from yer eyes.jpg
Connect the HIGH PRESSURE GAUGE on the other end. Don't make the mistake of connecting the lower ranged pressure gauge - you'll blow it out with 170 odd bar on it


locate the pressure relief valve.jpg
Locate the pressure relief valve - it is adjusted by undoing the lock nut and then inserting a 5mm allen socket and tightening to raise, or loosening to lower the pressure. The access is poor and I just could not get a regular allen key in there so I used a socket insert thiingymajig......

i used an allen key sockety thingy.jpg
.......like this.

allen key inserted.jpg
Insert the socket and figure a way of adjusting it. I used pliers.....


adjust relief valve.jpg
.....like this.




TO ADJUST THE PRESSURE:

1. Start up the engine, ADJUST TO MAXIMUM REVS then drop the handrest to activate the hydraulics.
2. Raise the dozer blade and hold it against the end stop to maintain the pressure and activate the relief.
3. Check the gauge reading. If it's too low [mine was 85 Bar] adjust up in stages to 170 Bar, or thereabouts. No more than 175 Bar though, according the official Volvo service manual.
4. Keep a check on yer hoses for new leaks under the higher pressure.


Remember, if your machine is older, or new to you but secondhand [like mine] the pressure relief may have been set lower to hide problems.


Mine adjusted up to 170 Bar and there have been no problems....yet!

I only adjusted this one setting. There are 2 others but my little EC15 is working fine, so, ".....if it ain't broke...leave it alone..."

[Muz]

Excellent .. so I assume this is what Volvo call the main relief ? I thought there were 3 ? .. I'll need to check my paperwork

[jackpreacher]

Excellent .. so I assume this is what Volvo call the main relief ? I thought there were 3 ? .. I'll need to check my paperwork

Yeah, there are three but I only adjusted P1 (referenced in the service manual) because everything seemed to work after that!

[Muz]

Oh ok .. well 2 of mine are gonna get the treatment next week when they come back in .. thanks for the heads up Jack .. think Im gonna have to get me one of them thar workshop manuals for those machines .. isnt that what the stealer is for ? you give him your custom then ask for advice when you have a problem .. but they just look at you blankly half the time

[Muz]

I see the difference now Jack .. the 'B' only has one main relief going into the block.

I checked one of mine yesterday, because I thought the tracks were down in power a bit, but it turns out they are fine. The operating pressured showed 170 Bar, and I think its just the way these machines are plumbed.

When you track and let go one lever, instead of deviding the flow evenly to each track .. it doubles the flow to the lever you still hold on, you can see this because it makes the machine quite quick to turn, as long as theres not too much resistance. However it seems to also reduce the power in this track, when it does so, giving the effect that it is 'weaker' .. But my tests seem to show otherwise

[jackpreacher]

I see the difference now Jack .. the 'B' only has one main relief going into the block.

So you have only 'B' models as well? I figured you'd be a bit posh and have an XT.....you advertise them with extending track I'm sure......

I checked one of mine yesterday, because I thought the tracks were down in power a bit, but it turns out they are fine. The operating pressured showed 170 Bar, and I think its just the way these machines are plumbed.

When you track and let go one lever, instead of deviding the flow evenly to each track .. it doubles the flow to the lever you still hold on, you can see this because it makes the machine quite quick to turn, as long as theres not too much resistance. However it seems to also reduce the power in this track, when it does so, giving the effect that it is 'weaker' .. But my tests seem to show otherwise

Yeah, I'd agree with that except that the flow possibly returns back to nominal after a few seconds with the one lever still held - well, that appears to be the case with my EC15B.

Anyway, are you happy with the results?


My far better half was dozing/grading gravel around yesterday in Doug [the digger] ...seemed effortless....I do wonder why the system pressure may drop over time though...... therefore requiring another relief adjustment - there's only so far it can go!

[Muz]

So you have only 'B' models as well? I figured you'd be a bit posh and have an XT.....you advertise them with extending track I'm sure......

My last XT's were 04's so older actually .. dunno how they designate them now ?

Anyway, are you happy with the results?

No actually .. cos I dont remember them being that weak .. I had one punter last year with one sat on his front grass which he was removing, the digger had new tracks so had a good grip, but wouldnt turn on the deep mossy grass .. so I brought him another at great inconvenience and it was exactly the same ?

I wonder if theres anything else up ? .. suppose I'd have to get the guage in line to the motor and re test next.. seing as the block relief is good .. cos it should be 170 Bar down there too at full relief

[jackpreacher]

I wonder if theres anything else up ? .. suppose I'd have to get the guage in line to the motor and re test next.. seing as the block relief is good .. cos it should be 170 Bar down there too at full relief

I'll check the service manual in the morning and see what it says about the travel motor hydraulics. One thing though Muz, last week or so I adjusted to 150bar'ish first, then finally to 175 - the SM says to go to 170 bar +\- 5 bar. Even that extra 20bar made an enormous difference to the travel performance. Is your gauge calibrated? Unless a gauge is a decent Budenberg or similar they don't really last long, especially these higher pressure cheapies. My tyre inflator gauge reads 60psi just sitting still........I have to add the inflation pressure to 60psi......looks scary if you're not in the loop of knowledge!

[jackpreacher]

I read through the Service Manual chapter on the travel hydraulics thoroughly and there is nothing to adjust other than the main block relief. However, I can scan the pages and post them here in case I got that wrong....just let me know.

The manual is very detailed about the planetary/reduction gearbox so that if there were any problems with the motors there is a seal kit readily available and the overhaul looks [] easy to my untrained eye. It covers the EC15 & EC20

[Muz]

Nahh .. thanx mate ... dont go to any bother .. I think what you said about being a few bar out, and the possibility of the guages having error might be the answer .... I'll jack them up to 800 bar and see if that works ... only joking internet people

[Muz]

I'll check the service manual in the morning and see what it says about the travel motor hydraulics. One thing though Muz, last week or so I adjusted to 150bar'ish first, then finally to 175 - the SM says to go to 170 bar +\- 5 bar. Even that extra 20bar made an enormous difference to the travel performance.

Had another EC15 with weak tracks lately and I was speaking to Volvo's top guy for compact stuff this afternoon, and he filled me in with the settings for this job, and I had forgotten this thread existed ... but thats one EC15B back up to spec now.

The bit Ive highlighted above is indeed very true

[Muz]

Uffex's post



sorry to tell you what you most likely do not want to hear, hydraulics are not self adjusting, a few bars pressure difference are unlikely to be reconciled by any operator. Worn machine will have little to gain by any magic adjustment. Real sorry if this is news too U.
Kind regardUffex

[d4c24a]

missing post

where did the post by uffex disappear too

[Muz]

where did the post by uffex disappear too

It tripped the spamometer .. but its passed muster, after review why do you ask ?