fc203a7e   
   On Fri, 16 Jan 2009 18:58:29 -0800 (PST), al  wrote:   
      
   >On Jan 16, 4:30 pm, 1991 Yota (1...@nowhere.com) wrote:   
   >> On Fri, 16 Jan 2009 07:10:50 -0800 (PST), al  wrote:   
   >> >Sorry to hear of your problems.  Let's look at the most critical thing   
   >> >first - the brake failure.  A common brake failure is an internal   
   >> >master cylinder leak.  No brake fluid leaks outside.  Instead, the   
   >> >internal master cylinder seals fail and the fluid can't maintain   
   >> >sufficient hydraulic pressure.  Hence, no brakes.     
   >>   
   >> And apparently this type of truck has a MC with two pistons, according   
   >> to the shop, and when one fails, it bypasses the other, so you don't   
   >> get stopping power.   
   >>   
   >> I did notice the next morning when I pulled it out of the driveway   
   >> into the street so it could be loaded up on a flatbed to be towed to   
   >> the shop, that I had some pump (resistance against the pedal) back   
   >> again. Not a normal amount, but *some* whereas I had virtually none by   
   >> the time I crawled back in the driveway when the incident occurred the   
   >> afternoon before.   
   >>   
   >> >This type of   
   >> >failure often can occur not long after any type of brake work is   
   >> >done.  If the shop tries to bleed the brakes and does it the old   
   >> >standard way of opening the bleeder valve and repeatedly pumping the   
   >> >brake pedal to the floor, then the piston and seal in the master   
   >> >cylinder can travel into parts of the master cylinder that are no   
   >> >longer perfectly smooth.  The rubbing of the seal against the rough   
   >> >portion of the master cylinder bore can lead eventually to seal   
   >> >failure.   
   >>   
   >> A really good point... hadn't thought about that. (My brake work was   
   >> done a year or more back, but that's interesting.)   
   >>   
   >> >The grease on the underbody almost certainly came from a ruptured CV   
   >> >boot.  I don't know where you live but premature boot failure often   
   >> >happens happens during cold weather when wet dirt and ice get impacted   
   >> >in the folds of the boot and then freeze solid.  This condition can   
   >> >rupture the boot as the boot tries to flex with hard, dirty ice frozen   
   >> >to it.  The key to long boot life is to keep them clean and supple.   
   >>   
   >> I live in SO CA, and while we did have a cold snap a few weeks back,   
   >> it's not brutal weather here. What can I put on the boots to keep them   
   >> supple? They stay clean b/c the truck sits pretty high off the road.   
   >>   
   >> >Hope all this helps.  Good luck.  Al   
   >>   
   >> Thanks so much --   
   >   
   >It is good policy to clean the CV boots whenever you have the tires   
   >off.  Simply rotate the wheel with the steering wheel fully turned in   
   >one direction.  That exposes all the folds of the boot.  Cleaning them   
   >with any solvent, WD40 or the like, is fine.  Once clean, treat them   
   >with silicone lubricant like you would use on any rubber   
   >weatherstripping.  That methodology should increase the life of the   
   >boots greatly.   
   >Good luck.  Al   
    The OP said the boots were replaced a year or so ago. They should not   
   have deteriorated in that time.   
   On my 88 Chrysler I replaced at least one boot per year - some years 2   
   - and not due to deterioration. They got damaged by winter ice. Rip   
   them right off.   
      
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    * Origin: you cannot sedate... all the things you hate (1:229/2)