Over the last two days, with the help of a friend, I successfully replaced my fuel pump in my 1999 Winnebago Chieftain 33B. I wanted to share my lessons learned but first I want to thank Subford, TeJay, Jagtech for helping with my troubleshooting last week. Thanks much guys!!! That thread is
here. Mine was challenging because it's a 15 year old coach and the rear jack bracket goes right under the fuel tank. It would be impossible to drop the tank without removing the jacks first.
First, you WILL need another set of hands for this project. I typically do all my own work and I'm no stranger to swapping axles, engine mounts, transmissions, transfer cases, etc. (Off-roading is my 2nd love, next to camping). Believe me, you will want another person!
Tools: Socket sets, pry bars, flat-head screwdriver, crowfoot socket ends, fuel line disconnect tools. The only special tool I needed was a welder. It was an unexpected set-back but I was able to rent a mig welder from Home Depot. More on that later.
If your coach has a spare tire like mine I highly recommend you take it down and move it out of the way.
Once per day for the three days prior to starting the work I rolled under the coach and soaked all the bolts in PB Blaster. HIGHLY RECOMMENDED!
Starting out I used a crowfoot to disconnect the hydraulic line on teh individual jacks. You will not be able to get to the nuts with a conventional open-end wrench, not even a stubby. The crowfoot made quick work of the hose connection. I zip-tied the ends of the hoses in plastic bags. Since the jacks are up there isn't any pressure in the system. Nevertheless fluid will leak out. All-in-all, I lost about 1/4 cup of fluid. BUT where fluid leaked out, air seeped into the line. I need to bleed the rear jacks.
LESSON 1: Buy and use caps for the hydraulic hose and the jack itself. this will not only keep your fluid in your system but will save you from having to bleed the system later.
We disconnected the electrical connector and clipped the necessary zip-tie.
Once the jacks are disconnected from the hydraulic line and electrical connector you can unbolt the bracket and lower the jack bracket to the ground. There are 4 bolts on either side. Thanks to the PB Blaster the right side came out without a problem. The left side, on the other hand, is where my story gets interesting. One bolt came out with relatively little trouble. The other three were super-tight, despite 3 days of soaking with PB Blaster. We tried several times but couldn't get them to move. I didn't want to break the bolts so we soaked again in PB Blaster. None of these bolts would move. I said to hell with it and got my cheater bar onto my breaking bar and pulled. Sure enough the first bolt broke. Oh well, can't stop now, I broke the other three bolts with the expectation that I would be drilling out these bolts later.
Once all 8 bolts were out of the jack bracket we slid it down to the ground. We had to use my floor jack to raise the rear of the coach at the hitch receiver so that the top of the jack bracket would clear the sides of the tank brackets. We did need to use a pry bar to get the bracket past the first tank bracket. After that we were able to slide the bracket all the way to the axle. There it sat for the rest of this repair.
Now were started removing the tank bolts. 16 bolts came out without incident. THANK YOU PB BLASTER! We positioned my floor jack under the center of the tank using a piece of wood between the jack and the tank. We also positioned two moving dollies, one at either end of the tank, to set the tank on. We put pressure of the jack and removed all the bolts. We slowly lowered the tank but found the front of the tank was hung. A quick pry with a pry bar broke the front end free. The tank slowly came to rest on the moving dollies. We were able to reach the fuel lines and disconnect them without issue. We plugged the rubber line going to the generator and put the main line and return line in an old plastic coffee container. We disconnected the vent tube and rolled her out. We needed to raise the rear of the coach about an inch so the tank would roll out without hitting anything.
Now we have tank out in the driveway were about to remove bolts. First we used a small steel bristle brush and cleaned the exposed threads of each bolt. Then we used PB Blaster on all the bolts and let it sit for about 20 minutes. Using a box wrench we slowly removed the nuts. Working back and forth, back and forth, we eventually got 5 of the 6 nuts off the studs. The last one proved a little more difficult and ended up breaking the stud. LUCKILY it broke high enough that it left enough of the stud to put a screw back on and get almost full thread coverage.
LESSON 2: While cleaning the stud threads you could also chase the stud threads with a dye to clean out the rust and debris that the brush didn't get.
We pulled the old pump out, compared to the new one to make sure it matched 100%, grabbed the new gasket then we put the new pump in. Prior to screwing everything down I chased the threads of the nuts with the appropriate tap. Wish I thought of that before I tried to take them off. At any rate, after chasing the nut threads they went back on without issue. Torqued to 8.5 foot pounds per the sticker on the tank.
Time to inspect those rear jack bracket bolts. Well it turns out that during the factory assembly the IGNORAMUS not only welded the nuts to the frame but also THE BOLTS TO THE NUTS!

The only way to fix this was to remove the old nuts and weld on new nuts. I'm not a huge fan of grinders or welders around gas lines or gas tanks so we took the necessary precautions. The plastic fuel line brackets were pulled from the frame and the fuel lines were pulled forward as far as they would go then put into the plastic container and covered with plenty of old painting blankets. The generator fuel line was plugged with a stubby phillips-head and the cable clamp tightened. Then the rubber portion was wrapped in fabic and tied away from where we will grinding/welding. We used a 4" grinder with a cut-off wheel to get the old nuts off. A quick trip to Home Depot to rent a welder and we had the new bolts on in no time.
LESSON 3: Expect the unexpected!
Once the new nuts were welded in I sprayed them all with some spray paint to keep them from rusting.
Now it's time to put the tank back. But first a quick trip to Napa to get new fuel filler line and vent line hoses because the old ones were rotted pretty good. The nuts for the tank brackets are not welded to the frame, instead they're set in clips that are clipped onto the frame. After rolling the tank into position we hooked up all the fuel lines and prepped the floor jack to lift the tank. After jacking the tank to the correct height we started putting the bolts in. It wasn't long before we found that several of the clips has been dislodged. We had to remove the bolts and lower the tank again and reset the clips. On the second attempt to raise the tank we went very slow. We pumped the jack twice then checked the clips, pump twice, check clips. It was slow and tedious but the tank was eventually raised into position. We put the bolts in and torqued them down. Don't forget the blue loctite!
LESSON 4: Go slow and be deliberate when raising the tank. If you don't have these clips then you're lucky!
Once the tank was bolted in we moved the rear jack bracket back into position under the tank. We raised the rear of the coach again to make getting it into position easier. Then we raised the jack bracket and put the bolts in (with loctite) without incident. Then we reattached the hydraulic lines and electrical connections and zip-tied the wires as appropriate. I still have to bleed the jacks.
All in all it took us about 14 hours; 8 on Saturday and 6 on Sunday. That includes all the trips to Home Depot, Napa, and pauses to eat and such. It's a big project but it can be done in your own driveway. My local RV service center quoted me $800-$1000 to do the work. I wasn't about to pay someone that much unless I tried and failed first!
Hopefully you can take something from my experience and make yours that much better.