Fuel pedal does not return

[MAJOR]

The hand throtle and foot pedal seem to lock up , need to manually return the foot pedal . ---- needs adjustment of some type ??? THANK YOU FLU-419 SEE

 

[Scar59]

Crawl under the vehicle, you have a return spring off the hook or broken. Get soldier B to actuate the pedal and you'll find the issue. Hand throttle linkage may be fouled w/ foot throttle.

 

[The FLU farm]

You may want to read the SEE, HMMH and HME thread. Just recently the subject of getting the throttle linkage unstuck was covered there.
Actually, if you read that thread from start to ever-expanding-finish, you'll find more info than most can absorb in a single read.

 

[MAJOR]

Crawl under the vehicle, you have a return spring off the hook or broken. Get soldier B to actuate the pedal and you'll find the issue. Hand throttle linkage may be fouled w/ foot throttle.

Thank you ,Ray

 

[MAJOR]

You may want to read the SEE, HMMH and HME thread. Just recently the subject of getting the throttle linkage unstuck was covered there.
Actually, if you read that thread from start to ever-expanding-finish, you'll find more info than most can absorb in a single read.

THANK YOU,Ray

 

[MAJOR]

throttle stuck

Could you give me a date of the thread on stuck Throttle you spoke of , I would like to review it. appreciated and Thanks again.

 

[The FLU farm]

It wasn't that long ago, as I recall.
Nothing personal, but I rather you spend the time finding it than me doing it.
Although, if my back gets any worse I may not be able to do much else than stare at the computer screen, in which case I'd look it up for you.

 

[crunchylicenseplates]

It wasn't that long ago, as I recall.
Nothing personal, but I rather you spend the time finding it than me doing it.
Although, if my back gets any worse I may not be able to do much else than stare at the computer screen, in which case I'd look it up for you.

I thought I'd take a look here and I see someone else has the same issue! Only to read that it's buried in the FLU thread. Not owning a FLU I thought I could learn some good info by reading the thread. I started at 309 and worked backwards to page 99. Not anywhere did I find a length discussion about the fuel pedal getting stuck. There were two posts about some FLU419's with bent throttles from not getting any WD-40, but that was it. I tried using the search function multiple times to no avail. After several hours of committed reading I throw my hands up.

Please kind sir, could you PLEASE drop a link to the page where the posts are that discuss this topic, or at least answer my question here?

My beloved 404s used to live in the dry climate of Wisconsin, and apparently the wet air in the deep south has infiltrated the grime, grit and old grease in the ball joints, spring and assembly of my throttle control when I push the fuel pedal down, the throttle is at about 1/4 engagement and does not return all the way. With the dog-house off I have to reach down and pull the throttle assembly arm back by hand. Which might be ok if I liked having my right leg cooked by the engine. In a manner of troubleshooting, disconnecting the arm to the carb didn't help, I'm at the point of needing to pull out the U-Assembly and clean all the moving parts, and replace the moving parts and cleaning all the travel points for the rods. I'm held up by two problems.

One particular issue I'm having that I was hoping this "discussion" would reveal, is the ball joint that attaches from the rod eminating from the pedal to just above the spring. I can pop it off partially but not all the way. Are there any secrets to dislocating these two?

Where #36 connects to #8



I spoke with the folks at EuroTech and they suggested there is a Zerk behind the pedal? Which is not in the diagram and I can't see when looking at the pedal in person or feeling behind it. Perhaps it's accessible from under the truck and I just didn't look hard enough? Do tell.

The other issue is more of just rust and old screws, taking the vertical plate of steel that stands from the floor to where the dog house connects to the right of the driver footwell seems impossible. If I do need to access replacing the ball joint where the fuel pedal attaches to the rod going to the throttle assembly, I've been hitting it with my favorite rust penetrant (Liquid Wrench and now WD-40 penetrant gotten TruckPro), maybe that will losen the screws. Anyone have to do this before?

A few colleagues suggested soaking all the grimy parts in GumOut.

Any suggestions from anyone on how to proceed?

Thank you in advance.

 

[The FLU farm]

Subconsciously inspired by you, perhaps, the other day I took the doghouse off on my SHEE, since the throttle felt overly stiff and did hang up once or twice shortly after getting it.
After doing nothing more than spraying some lithium grease on all pivots points in the linkage, it loosened up quite a bit. I'd imagine that after a bit of use, it'll improve even more as the lube works its way into things.

In your case, it sounds like disassembly might be in order, followed by cleaning and lubrication, and maybe replacing missing and/or tired springs. You may also need to adjust the length of the rods to get the pedal where you want it to be.

I didn't think to look, but judging by your illustration, those rod ends should come apart. Try a bit more force, and maybe with pliers rather than a screwdriver, to distribute the load better.

For a good penetrant, since trying it for the first time on my stuck backhoe pin I have become a firm believer in the 50/50 Acetone and ATF mix. The oil can I keep it in has a crimped bottom, and the mix actually makes it through that.

Anyway, the Unimog is nothing more than another piece of machinery, so whatever methods work on other things will work on Unimogs, too.

 

[911joeblow]

The linkage gets bent on these too if the dog house gets dropped on the linkage when being installed or if the cab was tilted and dropped crooked too. Mine was all bent up and all the rods needed to be straitened and lubed...

 

[crunchylicenseplates]

Subconsciously inspired by you, perhaps, the other day I took the doghouse off on my SHEE, since the throttle felt overly stiff and did hang up once or twice shortly after getting it.
After doing nothing more than spraying some lithium grease on all pivots points in the linkage, it loosened up quite a bit. I'd imagine that after a bit of use, it'll improve even more as the lube works its way into things.

In your case, it sounds like disassembly might be in order, followed by cleaning and lubrication, and maybe replacing missing and/or tired springs. You may also need to adjust the length of the rods to get the pedal where you want it to be.

I didn't think to look, but judging by your illustration, those rod ends should come apart. Try a bit more force, and maybe with pliers rather than a screwdriver, to distribute the load better.

For a good penetrant, since trying it for the first time on my stuck backhoe pin I have become a firm believer in the 50/50 Acetone and ATF mix. The oil can I keep it in has a crimped bottom, and the mix actually makes it through that.
Anyway, the Unimog is nothing more than another piece of machinery, so whatever methods work on other things will work on Unimogs, too.

I? I inspired you? Now that made my day! I'm glad I inspired someone this week.

You might be interested to read I did hit it with the lithium grease, first from a tube, then by spray (Liquid Wrench brand), and after a week of torrential rains and lots of humidity it seems to have gummed up again. Either I'm not doing it right or something else is amiss. Time to take it out and clean it all out.

Disassembly, agreed. How'd you know I tried a screwdriver?! I'll get out my Klein linesmans and give it a gentle tug. Thanks for the tip on the penetrant mix.

To 911JoeBlow's comment, I considered that too, the throttle linkage cable may be suspect as well, it does not appear to have been oiled much so after lubing it up, if it's too dry, then $7 from EI will get me a new cable and it's easy to replace. I actually already got the return spring, 2 of the end connectors with the round ends and the connecting rod to the carb (just in case). Only other question I have is, when I take the U Throttle Bracket off (#3 in the diagram above), there are 2 (8mm?) bolts holding it to the engine. Are those two bolts holding anything else together that I should be worried about?

As FLU's and 404 mogs share the same type of assembly I figure this info might be useful to anyone else. I was wondering if MSMog had run into this too as he's in the same climate I am.

 

[crunchylicenseplates]

I am happy to report that after putting in a full day of work everything is working again, and some.

While I did not pull everything out, after more close inspection, along with some logical thinking (ie messing with it) I determined that it was the throttle cable itself. The cable is housed in a metal sheathing and it was dry as a bone. As there is a slight bend in the cable the cable attached to the U-joint was getting caught up on the curve descending from the throttle cable, when I pulled the throttle back it caused the rod going from the U-Joint to the pedal to bend as it pushed back on the resistance and then it would snap into place. It would be at his point of resistance where the pedal would get stuck on return. The return spring wasn't powerful enough to pull it back past that friction point.

Using canned Liquid Wrench oil I squirted shots of oil from below and from above into the throttle cable sheathing, working the throttle and going back every 30 minutes or so and hitting it again (while I worked on other stuff). I did hit all the joints in the throttle assembly with more lithium grease, and oiled the pin on the fuel pedal, and now it works very well.

I learned a lot about which metal plates connect to what and that the rails for the seats differ for passenger and driver (because I put the inside rails back on incorrectly only to find I had to pull it all apart and swap them. Also found where a previous owner had ripped out the driver seat and broke the metal hole where the right side rail for the chair attached to the chassis. It had been kludged back together with a piece of steel (like a big washer) from underneath. Made for real joy when I took it out and putting it back in (twice).

In between oil shots in the throttle cable, I managed to do some rust rework in the cab using some Rust-B-Gone and lots of sweat equity managed to make the cab look nice again with some RAL6014 paint I custom ordered from Low Volume Powder in Texas ($25 for a spray can if anyone is interested). When the center metal plate and seat rails were out of the truck I took an opportunity to de-rust them and paint them. Also cleaned out the tool box under the passenger seat, saved it from rust and repainted it, the big one was the footwell on the driver side, that stuff got the metal back to it's original shiny self before I primed it and painted it. While it's not Maaco, it looks a lot better than it did. I even managed to get rust off from the pedals and from behind the fuel pedal and reworked that too.

Also took some time work on re-seating the canopy and start work on reworking my battery cables getting them ready for my new AGM batteries. Will finish that up tomorrow.

When I buttoned it all back up, it looks pretty darn nice.



And the fuel pedal doesn't stick and the throttle hand control is working great.

 

[tennmogger]

Way to go! Is that a fan on the floor to the left of your left foot, under the dash grab handle?

Nice truck.

 

[The FLU farm]

Hey, glad to learn that you got it working well again!
And it looks like you've taken after General Hood, making things nice and shiny. Time for some floor mats to protect that nice floor.

 

[crunchylicenseplates]

Way to go! Is that a fan on the floor to the left of your left foot, under the dash grab handle?
Nice truck.

Thank you.

Will be ordering more of that LVP paint. that one can went a LONG way, the inside of the cab will be completely redone in the proper RAL6014 green. The outside on the other hand will have to think about that one. Turns out that the truck has 2 coats of paint on the outside. The original RAL6014 and then another put on by previous owner, there's a paint can in the back with a custom color label on it. Not sure what I'll do going forward. I saw some pictures of some 404s in SoCal with GunMetal Blue on a black painted chassis. A friend of mine owns a custom auto shop and said I could use his paint spraying bay when the time came to redo it.

TenMogger, that fan is the part of the cab heater. When I was reading the manual for the first time, I was like, hmmm... there should be a cover there, I found the cover is in the koffer in a drawer. It's missing some mounting hardware according to the chassis diagrams. A trip to Ace may cure that, I may attempt to re-attach it today. Will post a picture when it's back up. Will probably repaint that and the dog house too.

While rooting around with the dog-house off and seats out I found what I thought I didn't have (laugh at me if you like) the battery disconnect port below the driver seat, never though to look "under the seat in the footwell", now I need to order a battery key, my fuel pump switch is on my dash (and not wired to the ignition, yet) so I need that darned battery key. I also noticed in the center console an oddly shaped oblong rubber matting covering 4 knock outs. As I want to add a back up alarm, strobe light and some 24VDC CREE LED and Xenon Hella work lights, I'll need to invest in some more switches, at least I know where I can put them now.

On a side note I even managed to find a label for the fuel switch on a Germany auction site. I found that by searching the popular auction site with the .de web address, I was able to find many 404 parts with worldwide shipping that were not on the domestic site.

Todays project involves getting my new Group 27 AGM Batteries from Batteries Plus in my battery box. My battery box is not the best of shape, it's suffered a lot of rust damage, these batteries are pretty heavy (65lbs ea I think), may need to replace the box and the cables, another project for another day. For the time being I need to rework the cable connections and find myself some 1"+ adhesive lined shrink tube and some quality battery terminal covers all the auto parts places round here have the crappy plastic ones.

Ultimately I need to make my own cables and replace what's in the truck, would anyone know the terminal lug size of on the battery disconnect below the driver seat? The picture on the EI site doesn't say how big these are.

I realize this thread is off topic already with this post. Yet as I've found much good info on this site are buried in the threads of other discussions.

 

[crunchylicenseplates]

After I got the batteries in and removed the hornets nest that was starting to grow under the koffer side door, I took it for a spin around the neighborhood. Got more whimsical looks from the neighbors.
Then put it to work pulling a couple tree stumps in my front yard. Needless to say, a few of my wife's plants were sacrificed and I added some tracks to the front yard, got the best looks from folks driving by.
Next weeks project will be replacing brake lines (taking out pinched front left and right lines from vehicle transport), bleeding brake lines, patching holes in canopy, removing rust from mirror mounts, transmission drain and replacement with Redline MT-90, switch installation on dash, install 24v fan on dash (somewhere) and buttoning up leaks in the koffer. Camping trip coming up in a month and a 4th of July parade with the cub scouts. Have to get ready for that.
Floor mats ? (hmmm...) Have to think about that one though.

One thing is for sure, working on the Mog has been good for my diet, no need to do cardio when I can sweat off a few pounds working on the truck.
Thanks for your support guys!

 

[The FLU farm]

Floor mats ? (hmmm...) Have to think about that one though.

Ask General Hood if you can have some of his old ones. I believe he gets new ones every time he takes his SEE in for detailing.
They're the temporary kind, but still.

 

[crunchylicenseplates]

The saga continues... as I was traversing the flood waters in my neighborhood from Saturday's storm, I got the end of my block and my engine was over-revving as the fuel pedal did not return (again). I had to work the throttle knob and throw it into neutral, quickly pull the doghouse off and pull the throttle back with my right index finger. After having fun driving through 2' deep rain flooded streets I took her home. I pulled out the throttle knob and pulled up on the wire and bunch of rust and dirt came piling out with the cable.

I went back to it today and took the throttle lever out and pulled the throttle wire out. After removing the set screw at the end of the wire (don't lose that, parts places charge $9 for that), and removing the 8mm set screw that holds the sheath, then took a pair of Klein Slip-Joint Pliers and straightened the throttle wire end, then positioned the sheath so it was pointing straight down below the throttle lever. I pulled the throttle wire straight out of the sheath, along with it came this tiny little metal piece called a Crimp Sleeve.

Let me tell you if you have to do this, don't waste your time trying to take the sheath off, it's mounted to a shim that (IMHO) is welded to the underside of the dash. According to the picture in the M180 guide it's screwed on, even if it is, you can't get a screwdriver in there. There's two more screws clamping the metal sheath with 6mm hex nuts accessible from the cab with screws visible from the engine side but can't get to with any force because even a stubby screwdriver won't fit, the sheath itself is mounted at the mouth of the throttle opening in the dash.

Fortunately the plastic straw of spray oil fits perfectly. Just put a rag at one end and gently spray into the other end (if you don't you'll get oil all over the cab and you), pump it full of lubricant like Liquid Wrench or other oil lubricant of your choice. Then take your favorite de-ruster cocktail and with a wire brush scrub the throttle wire a few inches at a time so it's smooth from end to end. This prevents you from having to buy a new one, although they're only a few dollars.

Then slide the Crimp sleeve on first and slide that wire back down the sheath, the fun part is getting the bolt back into alignment with the washers and the throttle lever without dropping the washers onto the engine or onto your driveway. Then route the sheath back through the guide loop and clamp and tighten the screw and then set your idle screw.

Now it works as it should and doesn't get stuck (at least for now).

 

[The FLU farm]

The saga continues... as I was traversing the flood waters in my neighborhood from Saturday's storm, I got the end of my block and my engine was over-revving as the fuel pedal did not return (again). I had to work the throttle knob and throw it into neutral, quickly pull the doghouse off and pull the throttle back with my right index finger.

Let's hope that doesn't happen again. But if it does, it's quicker to put the tranny in a high gear and stall the engine than to remove the doghouse for access.

 

[Speedwoble]

The saga continues... as I was traversing the flood waters in my neighborhood from Saturday's storm, I got the end of my block and my engine was over-revving as the fuel pedal did not return (again). I had to work the throttle knob and throw it into neutral, quickly pull the doghouse off and pull the throttle back with my right index finger. After having fun driving through 2' deep rain flooded streets I took her home. I pulled out the throttle knob and pulled up on the wire and bunch of rust and dirt came piling out with the cable.

Since you are new to this, are you aware of proper procedures for fording 2ft of water? It should be considered for emergencies, not a Sunday joy ride. If you want to play in the water, buy a boat.
Have you checked for water in your wheel bearings? Have you checked for water in your differentials or transmission? Did you remove the plug from the bell housing so water drains out of the clutch? Did you dry your brakes? Just because you can drive through water, doesn't mean you should, and, if you end up in water deeper than the Mog can handle, it places you at danger and it places those people that have to rescue you in danger.