Jeep TJ & Jeep YJ fuel line repair
This guide will go over how I repaired the rubber supply and return that connected from the steel hardline up to the fuel rail on top of the engine.
Not exactly a plethora of resources on this, so if you have made it to my guide, and it is not how you would handle business. Take what you can and apply it to your own repair method.
Rubber fuel line on Jeep YJ is leaking
Overtime, 30 years to be exact. My rubber fuel line has completely decomposed, dry-rotted, and now is leaking fuel all over the place. This is about 3 days into ownership of my new 1991 Jeep YJ named ‘New Girl’. Of course, whenever buying any vehicle in any condition, it is an expectation a repair will need to be made. Fortunately, knock on wood, this has been the only major problem that needed a resolution.
The jeep YJ and TJ have many high-pressure rubber fuel lines across the vehicle. This is required to help with flexing that will occur both on and off the road. If no rubber fuel lines are used in a system, it will be left highly prone to cracking.
Jeep TJ & YJ Fuel Line Diagram
Tools and materials needed for a fuel line repair:
- 4′ 5/16″ High Presure Fuel Hose
- 4′ 3/8″ High Pressure Fuel Hose
- High Pressure Fuel Hose Clamps
- Zip Ties
- 9/32 Socket
- 10mm Socket
- 10MM Combination Wrench
- Flat Head Screwdriver
- Box Cutter/Knife
- PB Blaster/WD-40
- Tight spaces tubing cutter
- Fire Extinguisher
- Saftey Glasses
- Clothing you do not Care About
How much does it cost to for this project?
The total cost for me was – $42.99
If you need to buy all tools listed for about, expect an all-in total of: $165.00
How much would an auto shop charge? About: $180-$300
Jeep Wrangler fuel line repair guide:
Step #1: Cut Cut Cut
Cut away the nylon fuel line that is connected to the fuel rail on top of your engine. Underneath you will find the barb of the push-on quick connect fitting. (Both supply and Return)
Underneath the Jeep, you will find the rubber fuel hose, a crimp fitting, and a push-on quick connect fuel fitting. Do not cut the rubber fuel hose. Instead, use your small spaces tubing cutter, and in 3 sections on the crimp fitting cut all the way around. Do not cut the steel hard hose, cut the crimp fitting only in 3 places with equal spacing. This will allow easy safe removal of the crimp fitting. Once the crimp fitting is cut into 3 pieces it will be easy to use your cutters to cut each section off.
If you do not have a tubing cutter it is possible to use cutters on the crimp fitting to slowly cut from one side to the other.
WARNING: Make sure your face is not directly underneath the fuel lines. Fuel will begin to leak! Make sure you’re wearing your safety glasses and gloves, fuel burns not only the eyes but also your skin.
Step #2: Remove Fuel Hose
If you look up towards the intake manifold hanging off the engine you will see a small clamp and 10mm bolt that is backed by a 10mm nut. This will be frustrating if your jeep is any height other than stock. A good core workout at the very least.
Once removed, the entire hose assembly with the old rubber lines and the old nylon lines will come out easily. See the picture for reference.
Step #3: New Fuel Hose
Install your new rubber high-pressure fuel hose with high-pressure fuel clamps. It is important we only use high-pressure fuel clamps when working with fuel lines. Wire clamps, most of the time are only rated up to 30PSI. The common fuel system operates between 45-120PSI.
The nut on the fuel clamp is 9/32, I know this is inconvenient considering most wire clamps are 5/16 or 1/4.
If it is difficult to install the fuel line you can use either PB Blaster or WD-40 to help out. Both of these lubricants are oil-based and will not hurt your fuel system or engine.
5/16″ Fuel Hose Here:
3/8″ Fuel Hose Here:
If installed wrong, the vehicle will pressurize the return. This will not hurt anything perse, but it will not allow the vehicle to run. If this is the case after your installation, simply flip the lines.
Fair warning if you did get this wrong. The return will be highly pressurized now, and it will spray fuel as soon as the clamp is cracked back open.
Step #4: Secure the Fuel Lines
By far the easiest part of your repair today. Snake your 4-foot fuel lines into an S-like shape. This will allow the fuel lines to have room to stretch when the vehicle flexes and bounces down the road.
Secure both fuel lines to the existing fuel line mount on the intake manifold with a zip tie. Then add more zip ties throughout, securing both the supply and return together, and mounting the two to different areas you see fit.
Step #5: Inspect the Fuel Line System
Considering we are facing old fuel lines now that need repair, and these are not the only ones in the system. The entire fuel line system should be inspected; front to back.
Unfortunately, many rubber fuel lines are located on top of the fuel tank. The body must either be raised up with a lift, or the fuel tank must be dropped. Thankfully this is easier than it sounds. It will be around a 3-hour endeavor nonetheless.
I have not yet opted to drop the tank. I plan on adding a fuel cell inside the cab when I install my rear stretch to the YJ. You will probably be okay in tackling this another day. Be extremely vigilant of fuel drop underneath the vehicle until this is addressed. Fortunately, fuel evaporates quickly, but this is dangerous regardless. Not only for our environment, the ones driving behind us, our health, but also our safety.