|
Hi Bob,
Brake pedal to the floor is almost always the master cylinder unless brake fluid is evident at a wheel (split hose or caliper seal). If you can pump the pedal and then get it to grab then it's almost certainly the master cylinder. The bore may be worn unevenly so in certain areas the seal may not "grab" the walls and stay sealed under pressure. Of course not something you want to be driving with unless it was a short drive and you give yourelf like three times the normal braking distance to be able to drop down into 1st and use the e-brake to stop, while letting the pedal rise all the way back up and then sharply step on it to re-establish the seal and stop normally. Best not to try this in busy traffic.
Should be straightforward for an experienced mechanic to replace the master cylinder. A bench pre-bleed is recommended plus a full brake fluid flush using the recommended bleeding pattern (generally the longest brake lines done first), remembering that yours uses Volvo's dual triangular braking circuits as the 1989 240s did not have ABS.
Also a good time to inspect the brake hoses in case those are looking too aged and need to be replaced first. At the same time, have the pads and calipers checked in case any of them are in need of replacement.
At that age the pistons may be starting to seize, usually the rears are worst. As the seals start to wear, traces of fluid leak past the seal with the outside of the piston getting caked with dried brake fluid and grunge to the point it won't properly retract through the seal, plus an old worn seal won't pull the piston back as well as a new one when released. You're looking for unequal pad wear inside/outer pad, left/right side of car, or uneven wear up/down on the 4 piston front brakes. Once the pistons start to get frozen the wheel becomes more difficult to turn by hand. Significant scuffing and a bit of resistance when being turned is normal and will increase with seal wear and grunge. A good rule of thumb for when your calipers need attention is being able to use one hand to turn it by the tire and two hands to turn it by the studs when the wheel is off. Although there are aftermarket seal kits available to re-build your calipers, it's generally not economical for a mechanic to do that. It's really hard to know which re-build brands are the most trustworthy, just be sure your mechanic picks a semi-well known brand that looks like the originals, not too dirt cheap and ones that can be returned if needed.
I see in your subject line you've got a loose mirror problem that you didn't mention in your post. If it's the glass, not the mirror housing mounting being damaged or loose, then the mirror glass may be separating from the backing plate. If you can spread your hand out and rock the mirror pushing in on the corners then it may be a broken mechanism. Volvo used a couple of designs of attaching the mirror plate to the mirror housing, basically a plastic gimble ring. It's too easy to break it if you don't know what you're doing and force it.
Or it may be the mirror glass is separating. You may notice the mirror vibrating when driving. I had one separate so bad it was flapping from a hinge at the top and risked falling off and getting smashed. It's not uncommon so I'll carry on with tips here on how to deal with it while I'm thinking about it and have a spare moment.
The mirror glass is affixed to a metal backing plate with some kind of rubber bonding membrane stuck to the silvering. You just need to finish separating the glass from the backing plate so you can get a proper amount of glue behind it, just be careful not to damage the mirror silvering.
I've now done this twice with success. Tipping it up all the way and pulled out a bit at the bottom, it should be out enough to start getting a blade behind the glass. Use a blade like a narrow putty knife and carefully work back and forth breaking the membrane away from the backing plate and without damaging the silvering on the back of the mirror. It may come off unevenly from the backing plate and glass, so not to worry.
Your mirrors aren't heated so you don't need to be too thin with the glue. Marine grade silicone sealant works well for this job. Apply an even bead in a WW pattern inside an upside down U so as to minimize creating air bubbles or allowing moisture to get trapped. Put a small block of 2x4 against the glass, push in hard giving it a little twist back & forth to spread the glue then bungy wrap it tight-tight around the housing for a long overnight cure.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
|
