A Frequently Asked Question: How do I improve the function of my original
Thunderbird windshield wipers?
The most probable cause for Thunderbird windshield wipers not working properly
is because they are not used regularly. After years of very little use the seals
have dried out causing the wiper motor to be sluggish. The internal wiper motor
seals need to be cleaned and lubricated. The procedure to do this is as follows:
- Connect a clear bottle containing Dot 3 or 4 brake fluid to the inlet tube
on the wiper motor located under the dash. I use a plastic bottle with a
hole punched in the lid and a rubber vacuum hose that fits snugly on the
wiper inlet tube. The wiper inlet tube is located on the side of the motor
facing the radio.
- Turn on the wipers, run the engine at idle, turn the wipers and the vacuum
should suck the fluid into the wiper motor.
- Then work the wipers by hand until they work on their own. The brake fluid
will soften the dried leather seals in the motor.
- Make sure the vacuum hose is always below the level of the fluid. Also, to
prevent blade drag on the dry windshield, squirt soapy water on the
windshield, this will provide lubrication for the blades.
- It usually takes about a pint of brake fluid to complete the process. It’s a
good idea to have an old rag or towel on the floor under the inlet to catch
any drips once the fluid hose is removed.
- Run the wipers several minutes after the fluid hose is disconnected to
remove excess fluid from the wiper motor. There will be some white smoke
from the exhaust as the fluid is sucked into the engine. It will not hurt
the engine and will clear up soon after all the fluid is purged from the
- Also, check to make sure that the vacuum source lines are connected
correctly to the engine.
If this procedure fails to rectify the problem, the wiper motor must be removed
and repaired or replaced. For description and detailed photos see the article
titled Windshield Wiper Vacuum Source under the “Body/Suspension/Steering”