TMF5000QT

I just purchased an 88 5000qt and when i get going down the highway I notice the car begins to vibrate throught the steering wheel pretty bad and gets even worse during braking. I feels like loose lug nuts but those arent the culprit. I would assume sticking calipers but the slide pins seem to move very easily. I know my bomb is toast, and when i brake hard the pedal slowly moves closer to the floor with some pulsating (but not the kind you get from warped rotors because it does this even when the car is still). Im new to audis and have only had this car for a few weeks so any help would be greatly appreciated. Also if anyone has any info on how to troubleshoot afterrun turbo cooling pump and the injector cooling pump i could use some help with that, the afterrun rad. fan is working, although only on high speed.

RussB

The 5000TQ can be a wonderful car, but the typical owner doesn't maintain his car, so most of them today have the same problems as yours.

All these issues have been covered repeatedly in this forum. Use <a href="https://www.audiworld.com/search/">Search Forums</a>. Here's a list of components, in order, that you should check:

o Vibration while underway:

Front end:

Tie rod ends
Control arm bushings
Ball joint
Wheel balance
Strut mounts

Rear end:
Control arm bushings


o Brake pulsing:

Is ABS working?
Rotor runout: <a href="https://forums.audiworld.com/v8/msgs/75169.phtml">Shudder elimination</a>


o Radiator Fan
Resistor pack <img src="http://img.eautopartscatalog.com/live/thumb/G504037412KAE.JPG"> (in front of radiator)
Radiator fan thermoswitch in radiator
Fan speeds 1 and 2 relays
After-run thermoswitch
After-run relay
Read this thread: <a href="https://forums.audiworld.com/v8/msgs/78797.phtml">Fan troubleshooting</a>.


o Suggestions:

Obtain a shop manual now. The Bentley is complete but expensive. The Haynes is inexpensive but incomplete. An alternative is an annual subscription ($25 year 1; $15 afterward) to <a href="http://www.alldatadiy.com/">alldatadiy.com</a>: it's complete but terse (as is the Bentley).

Do your own wrenching.

Find parts vendors that aren't in the Audi dealer channel: Worldpac and IMC resellers for new parts; junkyards for used. (U-Pull-It yards can be goldmines.) Search this site's classifieds, www.audifan.com's classifieds, and eBay.

Browse this site:<ul><li><a href="http://www.sjmautotechnik.com/trouble_shooting/trouble.html">http://www.sjmautotechnik.com/trouble_shooting/trouble.html</a</li></ul>

CARSNPLANES

Having the bomb shot means you can now feel every pump pulse through your pedal. It means without the bomb, you are working directly from the pump , whish isn't designed to directly acuate the brakes. The bomb, or accumulator, when working, holds about 400 psi of hydraulic pressure, which when added to the system pressure of the pump, which is about 2500 psi, gives you a smooth, repeatable, brake pressure application, void of power pulses and pressure drops. The pump is meant to rplenish or "charge" the bomb and to aid in steering. You need to replace the bomb (about $250).

The other vibrations could be other worn steering/ suspension components that you'll have to dig into.