Volvo FL7 help

Thanks Guys. After taking your advice, shoving the stick forward worked at treat. It has 6 speeds with R (reverse) and "C" left front whatever that is. There are two switches on the stick, one red in front and one white on the side. There is a unit on the back of the gearbox that is either creeper or overdrive I have been told, but at present the wiring is broken off which I have to resurrect.
Main problems now are:
1. Cab still doesn't tilt. Replacement pump can pump pressure now but when the ram is in the cab down position the oil bypasses and comes back up the other line. Move the ram out a few inches and it starts to move and pressure builds. I am surmising that the ram bore is damaged at the end. Rust maybe??? There is some kind of valve built in which I figured out stops the cab from coming down unless pressure is applied to the "down side" fitting. It seems to be ok.
2. Fuel gauge doesn't work. Gauge itself is ok, getting 24V, and sender measures ok but wiring must be broken in between. Unfortunately it is difficult to track and the diagram that somebody very kindly put up here doesn't show those wires. Contemplating running a new pair of wires all the way.
3. Exhaust brake solenoid is permanently activated if you plug it in even though the foot switch is disconnected, and while activated air comes out somewhere so obviously a broken air hose or fitting somewhere or maybe the actuator itself.

I won't touch the deck until it is running and registered, meantime try to get a measurement of the excavator and dozer height.

Not that I'm an Ovlov man, but the "C" on the gear knob is crawl, otherwise known as bog cog by the rest of us.

My post explained the two switches as well as C gear. Maybe Swish will do a vid of going through the 12 ;)gears

Thanks Mamoth. Splits, ranges... I am a computer Dude so most of that went over my head. I don't want to drive the thing, just need to understand it to fix whatever I can. There is a solenoid on the back of the box that must be the creeper, but it is disconnected. The driver that delivered it said he didn't touch the second switch and he was ok with the 12 speeds, so I assumed it muct be creeper. Dilemna though, if C on the selector is creeper (straight ahead from reverse) then why is there a switch. Sorry I seem dense (maybe I am...). Dunno how much must be running to get her registered, but I imagine such things would be checked.
Thanks again and keep the comments coming.

G'day TH, regarding the cab pump you might try checking the pump hoses are the right way around as normally when pumping the cab down when it gets to a certain point (almost right down) it will fall the rest of the way this is so the ram is free to move as the cab bounces up and down on the cab springs, may not be the problem but worth a try. Re the wiring at the rear of the box i suspect it would be either the speedo or switch for the high or low split light as both the range change and splitter are air opperated from the gear stick to the box, and by the way the splitter gives you a high and low in each gear just pre select high or low and when you press the clutch it should change. good luck Debo.

With regard to the exhaust brake mate.

Volvo's are set up so that when the hand brake is applied the exhaust brake will also be partly applied,this function is so that the engine can warm up quicker. This is due to Sweeden being a shade on the cool side during winter.

This could well explain why you have air supplied to the exhaust brake solenoid even though you've disconnected the switch.

Release the hand brake and see air is still supplied to the solenoid.

One also to watch for is when you release the hand brake,ensure that the 'Broms' brake button is also pushed in. This is a small black push in button to the left of the dash with a domed head. This is a Volvo safety function that will pop out is you've lost all air pressure.

Build the air up,release the hand brake and push in the 'Broms' brake.

I'm starting to see why Swishy 'aint too keen on Volvo's.

Good luck Jamie

Thanks Debo,
Worked through the hoses, they are correct as the pressure is applied to the hydraulic tilt locks first then the lift side (piston seal end) of the ram. (The locks hold the cab down until freed by hydraulic pressure from hte hand pump). It's odd, if I pull the ram out about 3-4 inches it works normally out to full extension, but as soon as it gets near the "home"end it just bypasses out the other cylinder connection back to the pump and won't lift the cab. The end of the cylinder has a little steel ball valve that stops oil returning to the pump (stops the cab lowering on its own) until a little piston on the lowering (return) connection is pushed over by oil pressure and unseats this little ball. Unless it has something extra internal like on the end of the rod there doesn't seem to be anything else that could be at fault. Logic would suggest it can't or it will never lift the cab in this design. The cylinder doesn't have a screwed end so not sure how or even if it can be taken apart to inspect. Unless you maybe pry out the dust seal and there is a circlip in there....
As for the wiring, it is definitely a solenoid that feeds an air actuator on the back end of the unit attached to the end of the gearbox. It's almost like an optional extra botled onto the back of the box that has 2 speeds, actuated by air. I guess I'll hook it up and assuming there are no nasty noises we can see how it behaves.

Thanks Jamie. That explains why it took me 15 minutes to get the brakes off when I tried to move it last time. Seems you have to hold that button in for a few seconds unless it is dodgy of course. Really appreciate the exhaust brake tip, I would never have known that one....
I am very impressed with the friendlieness and knowledge on this board. Well done All.

No worries mate.

I've a soft spot for FL7's,when i started out in my apprenticeship as a fitter the bloke I worked for had five of them.

Check that the exhaust manifold studs are all there,they have a habit of braking off.

Jack the front steered wheels of the ground and check for play in the king pins,they wear out. Grease them when the wheels are in the air.

The splitter or half gears are in the front section of the box and the range change is the back section. You'll see about one third of the rear section is bolted on,that's the range change.

There is an adjustment for the correct operation of the splitter on the front R/H side of the box. There's a bracket on the clutch fork shaft and an air operated cylinder with a plunger on one end. The gap between these two should be 13mm.
Get a half inch drive socket extension and use this to measure the gap.

Good luck Jamie

Mammoth
M80

RE: Maybe Swish will do a vid of going through the 12

No Not ever in a V truck
LOL

Mammoth

Q:?

a question on everybodies lips th@ aint ask n


Have U seen 2 new look n pots arrive from the left coast az yet?
LOL

www.hcvc.com.au/forum/YaBB.pl?num=1317897418/0


Thanx in advance
Cya
[ch9787]