Here's how to check and adjust the tension:
1. Locate the Tensioner: The power steering belt on a 740 Turbo is tensioned by a spring-loaded tensioner pulley. Locate this pulley; it's usually attached to the engine block and will have a spring visible.
2. Inspect the Belt: Before adjusting, visually inspect the belt for cracks, glazing, or fraying. Replace a worn belt, as adjusting a bad belt is pointless and potentially dangerous.
3. Check the Tension (the push test): This is the crucial step. Push down in the middle of the longest span of the belt (the part furthest from the tensioner). There's no specific measurement, but the goal is to achieve a deflection of roughly 1/2 inch (13mm) to 3/4 inch (19mm). This is subjective and relies on experience, but think of it as having a noticeable but not excessive give. If it's too easy to deflect (too loose), or very difficult (too tight), the tension is wrong.
4. Adjusting the Tension (if needed): The tensioner is usually a pivoting pulley with a bolt or sometimes a lever. This needs to be loosened to change tension. This is usually a 13mm or 15mm bolt. Refer to a repair manual as the exact location, size, and access to this bolt varies slightly depending on the specific engine type (B230FT is the likely candidate for a '88 740 Turbo). A repair manual will have a diagram.
5. Tightening the Bolt: Once you've adjusted the tension to the correct deflection (using the push test), firmly tighten the tensioner bolt.
6. Recheck the Tension: Always recheck the tension after tightening the bolt. If you've moved the tensioner, you may have inadvertently altered the tension.
Important Considerations:
* Repair Manual: A Volvo 740 Turbo repair manual is highly recommended. It will have detailed diagrams and specifications, making the process much safer and more efficient.
* Safety: Use jack stands to safely support the vehicle while working underneath. Never work on a vehicle supported only by a jack.
* Tools: You'll need a socket wrench, possibly a ratchet, and the appropriate size socket for the tensioner bolt.
* Belt Routing: Ensure the belt is routed correctly around all pulleys before tightening. A mis-routed belt can cause damage.
If you're uncomfortable performing this task, it's best to take your car to a qualified mechanic. Incorrect belt tension can lead to premature belt wear, pulley damage, or even power steering failure.
