Mountains

Mountains

Thursday, November 17, 2022

The Volvo 740 manual clutch situation is nuts.

 Years ago, the plastic clutch pedal in my Volvo 740 broke where the pivot meets the master cylinder cleavis. Cool. I put a huge bolt through the pedal with some epoxy and a band clamp and drove it for a decade before the epoxy broke and I had to redo the assembly. At least that time it failed in the driveway.

 Last week after a long slog through stop and go traffic, I thought the clutch was feeling clicky... like something was catching on the pedal. The next day I investigated, and after pumping the clutch a few times, it the pedal gave a pop sensation and went limp. A glance under the car showed the slave cylinder piston pushed out of the cylinder with a giant splat of hydraulic fluid. I gently reseated the piston, and to my surprise, the clutch works fine, though I have a new slave cylinder on order, as I think this means that there is a small air leak or contamination in the bore and I will be inconvenienced in the future if I don't get on it.

Of course, ordering parts was not straight forward. There's still a parts shortage from the supply chain problems, and there's mysterious gaps in the old-Volvo aftermarket parts catalogs. For some reason, IPD didn't list any cylinders for my specific model year. There are multiple types of clutch release arms, but the hydraulic ones are mysteriously hard to find. I want a clutch pedal I can trust to step on, but the OE plastic ones are seemingly no longer made, so you're on the hook for making your own or buying a metal one from europe.

Saturday, November 5, 2022

Volvo 740/940 Foglight Switch, General Dash, and Seat Switch Rebuild

The fog light switch in my 740 suddenly locked up and refused to actuate a few years ago. Because it's never very foggy, and for a while I had a modern car that I drove when the weather was ill, I put "new switch" on the list of parts to accumulate, and then stopped thinking about it. But, I recently had the opportunity to re-fix the clutch pedal that broke so long ago, and while I had the dash apart, I thought, "Why not".

The obvious answer being that 30 year old plastic is fragile and snaps at the slightest hint of stress. Kind of like me.

The dash plate pops out. The switch is disconnected from behind.

Switch slides out.

Switch comes apart by pressing in 4 tabs around the back. The switch action is a metal finger with a spring inside of a post.

The back half of the switch. Has the light bulb and the contacts. The mechanism sea-saws to open and close the contacts.


The reason the switch was stiff is that the grease inside the post had hardened and prevented the spring from compressing. Additionally, it seemed like the finger had oxidized a bit and expanded inside the post. I removed the grease, sanded the finger so it moved in the post freely, and then added new silicone grease.



'Reassembly is reverse"