Frequently Asked Questions

Below is a list of questions and answers regarding the belleville washer problem and the Jiffy-Fix solution. Please click on the subject link to jump to that part of the FAQ or scroll down to review.

Ordering Questions
Original Problem Questions

Bus / Brand Questions

Repair Questions

Support Questions


Where is the best or cheapest place to purchase these parts?
A All parts are available from Jiffy-fix on the website www.jiffy-fix.com or through authorized bus parts distributors.

Q How do I know what to order?
A Tell us if the Bus is front or rear engine. Any of the following information would also be helpful: The hose I.D, the hose O.D, if the hose is original equipment or if it has been replaced by an aftermarket hose

Q Are there any bulk discounts for fleets or wholesalers?
A YES. We could have someone from our sales team contact you directly. Do you personally make the buying decisions? If not, who does?


Why won't the same problem occur with these new replacement parts?
A All of the new parts are manufactured to OE specs from stainless steel (except for o-ring), which will not corrode or crack.

Q Why the switch to stainless steel?
A Stainless steel will not corrode and cracks will not form in the fitting's Belleville washer.

Q Why is this the "best fix?"
A This remedy allows for a quick, economical fix and ensures a complete, long term repair.


Is this a design flaw in the bus?
A No. The repair parts are an improvement.

Q Do all buses have this problem?
A It is our experience that, depending on the year of the bus, all Thomas buses from approximately model year 2000 to present that use a Quick Connect Fitting with a Belleville washer will eventually have an issue with either corrosion, cracking, or leaking.


How do I tell if I have a cracked washer on my connectors?
A Clean the grime off from around the connector and the tank where the connector threads into the radiator. This will allow you to check the washer for cracks. Not all connectors will leak if the washer is cracked, but they will leak if it is broken in more than one place.

Q Will the connector leak when the washer is cracked?
A Not at first. In time, more cracks and leaking will develop.

Q What might happen if we do not replace the quick-connect fittings now?
A Our investigations indicate that the connection is likely to leak. A bus that is leaking coolant will likely be grounded by the DOT. In rare cases, coolant and transmission oil can mix leading to an engine and/or transmission rebuild.

Q Should we replace every fitting even if they are not leaking?
A Yes! For the few extra minutes it takes to do both, why do the job twice?

Q Is it easier to take both connectors out at the same time?
A NO. Do not remove both connectors at the same time. The inner tank will drop out of its location and you will have to disassemble the radiator. Replace one connector at a time.

Q How do I know if the new connector is tightened properly?
A The torque specification for replacing the new connector is 26 Foot Pounds or 35 Newton Meters of torque. The installation information and specifications can be found on www.jiffy-fix.com.

Q Should we replace the hose ends (tubes) right away or only if they are severely corroded?
A We would recommend a total replacement, especially in the rear engine buses and in areas where roads are salted. This will prevent the Bus from being grounded in the future by the DOT due to leaking coolant.

Q The connections on my bus are too corroded to remove the tube. How can it be serviced?
A This is common, especially on rear-engine busses. The easiest way to service this joint is to cut the hose just past the crimp ferrule. The hose has a wire braid just under the cloth wrap. It can be cut by one of a couple of means, one way is to place a couple of layers of masking tape over the cloth and cut with a fine tooth bladed hacksaw. Be careful to clean the debris left by the hacksaw. Another way is to cut the cloth wrap with a knife then use a side-cutter to individually cut the wires, then continue with the knife to cut through the rubber core. The next step is to remove the old fitting/tube assembly and discard.

Follow the rest of the procedure on the documentation included with the replacement parts, or, as outlined on the website, www.jiffy-fix.com Remember, the replacement fitting and tube is made in the USA from Stainless Steel so you won’t experience that problem again!


Do you offer any technical support if we have questions?
A Yes, you can call the toll-free number 1-888-605-7788 and someone will be able to answer your questions.