Got a small intermittent brake fluid leak, apparently from the vicinity of the brake fluid reservoir. Just got home from a 2500 mile trip and initially noticed my foot was slipping on the clutch pedal. Last time this happened the clutch master was leaking on to the pedal. But pedal was dry. Found the carpet was wet. Figured that when I had the front brake cylinders a couple of weeks ago, dealer spilled some brake fluid when filling the reservoir. But it has kept dripping. Not when I am driving but overnight as it sits. It's dripping off the edge of the plastic dash bottom. Not much. A spot about the size of two quarters on newspaper in the morning. It's very hard to see in that area and I haven't opened it up yet to get a good luck. Has anyone experienced this problem? I assume there are a couple of feeder hoses going from the reservoir to the two masters under the dash. Anyone know how to disassemble that area to get a better look? It didn't drip after the last day of the trip so perhaps it was just a spill at the dealer and its finally ran dry, but I'm not optimistic that's the case.
99 FG Brake fluid leak
- Thread starter kerry
- Start date
Found this picture of a Fuso reservoir. Looks like it has three hoses exiting the reservoir and any of those fittings or hoses might be leaking.
http://www.ebay.co.uk/itm/Brake-Fluid-Reservoir-Bottle-2007-Mitsubishi-Canter-Fuso-/331790932276
http://www.ebay.co.uk/itm/Brake-Fluid-Reservoir-Bottle-2007-Mitsubishi-Canter-Fuso-/331790932276
I removed the lower dash piece, and the corner trim is separate, clipped to the dash. It can be removed once the lower dash is loosened. I could then see and get my fingers on the bottom of the reservoir. My tentative conclusion is that the leak was caused probably by both spillage when the reservoir was filled during bleeding and leakage from being overfilled. It was filled into the neck of the tank. I could feel fluid both on the bottom of the tank and slightly up the side. I don't think it could have gotten to those locations without running down from the top of the tank. I could see no obvious leaks on the hoses. I removed some fluid from the tank with a straw to get it below the neck. I'll keep an eye on it.
skippythedog
Observer
You might want to follow up and hose down the whole area w/ some Brakleen. That BF is pretty corrosive and will peel up any paint that it sits on. Put a huge wad of old towels/rags wherever you expect the liquid to puddle. The Brakleen will evaporate and leave no residue. It will even save your carpet and hence your floor paint.....Spray the carpet liberally and closely/forcefully from both sides. Follow up w/ some degreasing detergent (like Dawn dishwashing soap) and hot water.
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skippythedog
Observer
I've got to say, your "leak" is interesting though...overfills are really common on brake work where new linings were installed. This is because as the linings wear down and the wheel cylinder (or piston caliper on discs) become more extended, more fluid is needed to keep the reservoir topped off....Then they push the pistons back in for the new linings to clear the drums/discs and the reservoir overflows if they didn't suck any out. Also, if they overfill on the bleed and a big air bubble gurgles up to the reservoir, it can flow over.
Even if you didn't have new linings installed, your shoes may have been out of adjustment, so the same condition may have been present (pistons manually manipulated etc.).
When brakes are out of adjustment (like my rears are right now), you push on the pedal and if you release and push again rapidly, the pedal will come up a notch as the fluid replenishes the void....
If you don't have a leak now...and you don't have a leak when you tilt the cab, and your cap is in good shape....things sort of point to a one time overfill that collected in the crevices of your dash.
Cracked tanks occur too and act differently dependent on the temperature.
These are just random thoughts to help isolate the cause......peace of mind.
Even if you didn't have new linings installed, your shoes may have been out of adjustment, so the same condition may have been present (pistons manually manipulated etc.).
When brakes are out of adjustment (like my rears are right now), you push on the pedal and if you release and push again rapidly, the pedal will come up a notch as the fluid replenishes the void....
If you don't have a leak now...and you don't have a leak when you tilt the cab, and your cap is in good shape....things sort of point to a one time overfill that collected in the crevices of your dash.
Cracked tanks occur too and act differently dependent on the temperature.
These are just random thoughts to help isolate the cause......peace of mind.
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unkamonkey
Explorer
Carpet in a Mitso?
Ok, other than adjustments I have never had brake issues since 1998 in mine. Factory brakes are still on it.
Ok, other than adjustments I have never had brake issues since 1998 in mine. Factory brakes are still on it.
pugslyyy
Expedition Vehicle Engineer Guy
Hopefully that was it. I bled all new fluid through mine a few months ago and it made a huge difference. Bleeding the ABS is a bit of a challenge, and as noted you have to be really careful to clean up the spilled brake fluid - it is the best paint remover ever.
Some more info. After sitting outside my house last night after I drove it to our garage to unload the kayaks yesterday, there was a 1/4" spot of fluid on the puppy diaper so I disassembled the dash again and took another close look. Here's what I think is happening. At least two of the rubber hoses which lead from the tank to the master cylinders are covered with a second layer of vinyl hose which isn't a completely tight fit but has a gap at the bottom. If the reservoir is overfilled or spills over, the fluid will run down the side of the reservoir and then down those rubber hoses. When it gets to the vinyl covered portion it will continue to flow down the hose between the rubber and vinyl, pooling up in there. So when the vehicle tilts in the right direction, the fluid can flow out of the vinyl covered portion on the rubber hose and drip down onto the dash/transfer case bracket. At least that is the best explanation I can see so far looking at where the slightly wet spot on the underside of the dash was, directly below there the vinyl hose starts to cover the rubber hose.
Ended up taking the truck to the dealer since the brakes were pulling left anyway after their rebuild and they needed to adjust them. They discovered the leak was coming from the level sensor in the reservoir. Sensor and reservoir are one part. Here's the bad news. Mitsubishi doesn't produce or sell the tank anymore. Dealer has a junk 2005 Fuso on his lot and he's going to see if the reservoir from that truck will fit. If that doesn't work I guess I'll be contacting Busbee's or looking somewhere else for a new reservoir or somehow trying to figure out how to plug the leak. It's not a huge leak but it's a persistent one which puts brake fluid on the floor, then on your shoe and then your foot slips on the clutch pedal.
Dealer ordered a used brake fluid reservoir/sensor from Busbees and will install it. I told him to keep the old tank for me. I plan to plastic weld the sensor hole shut and keep it as a spare. Since my OE one started leaking, it seems to me there's good potential the used replacement will do the same. Do the Aussie versions have a build in fluid sensor in the bottom of the tank?
Busbees sent the dealer a tank from an automatic transmission FG. It's not interchangeable. It lacks the nipple for the line to the clutch master cylinder. So a longer wait for a correct used tank.
Seems like an odd choice to me. On Mercedes I have owned, all reservoirs are identical with all nipples molded in but sealed at the end. For automatics you just leave the extra nipple alone. For standards, clip off the end of the nipple and use it.
Seems like an odd choice to me. On Mercedes I have owned, all reservoirs are identical with all nipples molded in but sealed at the end. For automatics you just leave the extra nipple alone. For standards, clip off the end of the nipple and use it.
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