1977 RT620S Manuals

[Paragon]

Good day everyone,

I am looking for information and repair manuals for my 1977 RT620S grove.
At this time I am looking for info on the Swing Brake system.
The old crane works quite well but the swing brake doesn't hold on heavier loads.
Was wondering if it could be the slave cylinder (if that is what it is called) or for sure the brake pads or shoes.
Also wanting to see how hard the pads are to change.
Also all info about the old crane

Thanks
Stephen

 

[Paragon]

Here is a couple of pics

 

[kshansen]

Paragon,

Can't help much with the Grove but we have a RT63S that looks very close to yours. Just yours looks much nicer and cleaner! What engine does yours have? Ours is a 6V-53 Detroit. I'm guessing from the dual exhaust you have some kind of V engine in there. All I know about the swing brake is ours was not working at all and I filled the master cylinder and bled it out and operator was happy. I tried telling them that the system needed more attention but that fell on def ears. A dry system tells me something is leaking but what do I know I've only been pulling wrenches for 40+ years! It's been a while since I worked on the brake of ours but for some reason I am thinking it is a disc and caliper style.

 

[Knepptune]

Any grove dealer will have those manuals or will be able to get the pages faxed you need faxed over.

Ok the swing system. Yours may be different as its older. On top of the swing gearbox you will have the hyd swing motor. Under that will be the brake assembly. It's a two part brake. It has an internal spring brake and a hydraulic brake. They are fairly simple. It's hard to explain but easy to work one. Regular hyd system pressure is used to over ride the spring brake and the foot brake works off it's own system. The pistons are built into each other but they use the same brake pads. If it's in the pads neither system will work. Most likely the seals in the brake need rebuilt.

 

[Paragon]

Kshansen,
The engine is a V8 3208 Cat
Also found the master cylinder to be low and am guessing then it takes the same hydraulic fluid as the rest of the system as it is tied in.
The fill plug is stripped and had a copper plug installed. Probably the incorrect thread i am guessing and may be why it is stripped.

Thanks for the reply

 

[Paragon]

Knepptune,
I think I get what you are saying
The brake then would be on at all times until the swing lever is operated, this would allow for fluid to go to the brake releasing it while the swing was operated.
while swinging you would use the foot brake to control. Makes sense as I was looking for a brake lock for when the swing is not pinned. Also makes sense that with the foot brake working (at least partially, need to get the mater cylinder topped up as Kshansen said) that the seals for the swing lever to brake are bypassing and need repaired.

Thanks for replying

 

[Knepptune]

Not exactly. These have what they call glide swing. The swing should have an electric toggle switch or a pull knob to release the swing brake. It's like a parking brake on a truck.the crane will essentially free swing. The foot brake system is it's own circuit with nothing to do with the rest of the crane. Usually they require dot3 brake fluid. When you release the park brake hyd fluid simply overrides the spring brake. It may feed of the same circuit as the swing motor but has nothing to do with the lever. Hope this helps.

 

[Paragon]

Got ya,
The outrigger switch has three positions. One to extend them out, one to extend them down and has to be in center for boom to swing.
if it is in either direction other than center and the lever is pulled the boom will swing but just creeps very very slowly. it would take at least an hour to go 360 if not more.
so I am guessing that must be the brake? never tried to see if this would lock it when un pinned. Never took it out of center position when operating. I had thought this was for fluid flow to the swing?
I will try it tonight or tomorrow and see.

I do appreciate your time

 

[dbl612]

the outrigger functions work off the swing hydraulic circuit. the toggle switch just shifts the selector valve from outrigger operation to swing function. if the machine has free swing it will have brake pedal on the floor. if the machine is non free swing (locked swing) it has a spring-applied, pressure-released brake. when you move the swing lever in either direction, it first pressurizes the brake (releasing it) and sends flow to the swing motor to affect swing motion. when you let go of the swing lever, pressure is released from the brake (applying it) and flow to swing hydraulic motor stops.

 

[Paragon]

dbl612,
Ok, thanks.
So can you tell me where the brake Hold/ Release is on this model?
I have service/ operation manual ordered but am bloody curious!

Thanks

 

[dbl612]

do you have a floor-mounted foot brake for the swing?

 

[Paragon]

Yes, it is a floor mounted brake for the swing

 

[dbl612]

there should be a rocker-style switch on right side of dash or mounted in console on right side of ops cab.

 

[Paragon]

ok, so while actually looking for the switch and checking the pivot cylinder for wires running to it. I found that the brake disk is not in the oil. The peddle brake line splits and runs to 2 calipers, one on each side. On the rear dead center is a came style brake that is run by a cable that I am guessing runs into the front of the cab to an emergency brake style lever.
yes! obvious I know but, I tried it thinking that may be what it is for a couple of days ago and nothing! but was thinking it had to be a hydraulic brake and didn't bother to look close at things until tonight. A hydraulics guy I use thought along the same lines as Knepptune (without looking at it) so I never looked farther and went to this form.

 

[Paragon]

 

[dbl612]

old style brake. works well if calipers don't leak. foot pedal runs hydraulic calipers (just like auto disc brakes) and hand lever operates a cam type clamp for a separate parking brake (made by mico for grove). no electro operation (swing pump does not interact with swing brake at all). same etup was used on tms 300 series cranes of the same vintage.

 

[Knepptune]

Yep. I've never dealt with that setup. I knew grove had something like that but transitioned in either the late seventies or early eighties. We have an 81 rt740 and it's got the hydraulic setup.

 

[BTS]

Paragon, looks like quite the project. Check here for a number of manuals especially for when you get into the electronics: http://www.bodetechnicalservices.com/crane-technical-support