Date: Sat, 10 May 2008 19:44:56 -0700
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: Replacing the master cylider
In-Reply-To: <DEFA478AC15B480392C99100ED930251@ZoltanPC>
Content-Type: text/plain; charset="us-ascii"
Hi Zoltan,
I meant to send it to the whole list for sure.
It's a real bother to remember to paste and copy 'gerryvanaong' into the CC
box every time. Don't like that set up at all.
I'm on 10 groups btw, I don't think any of them are set up that way.
Here it is, if I can find it ( yes too much pride to ask - yes perhaps )
I will sign in advance this time.............
Scott
30 + years professional full time automotive technician, automotive repair
and consulting, 25 years my own business. Started it June 1st, 1983. I've
worked on 10,000 cars I'll bet. I calculated roughly 7,000 car jobs alone,
during 13 years in Sausalito, Ca 1986 to 1999.
Vanagon, and Vanagon Engine Conversion Specialist.
( and I'll get in trouble for not trimming posts.
I'll trim what I can. )
Zoltan wrote to me just now, after sending a thing to just him,
"Super help, Scott. Thanks.
I think, it would be great if you would send it to the list also. They want
to know, believe me. Only have too much pride to ask.
Z
And here's the document : it's about Vanagon Brakes , this one, what wears
the most, the least etc.
WHAT WEARS MOST : ( by Scott Daniel Foss, Turbovans )
ONE. Brake fluid deteriorates. It absorbs moisture out of the air. Just
sitting there, it is absorbing moisture out of the air, and deteriorating.
Max two years life.
< a side note if you can handle it - the reason a GM car has a rubber
flexible diaphragm under the brake reservoir lid is so that the brake fluid
can be isolated from the ambient air, yet the fluid level can go down as
brake pads where >
TWO - rear wheel cylinders. They are the hydraulic component that will leak
first. Changing fluid helps prolong their life. I only use german ones. No
Mexican or Brazilian or whatever. Pull back the rubber boot with s small
screw driver, if it's wet under there, it's leaking.
THINGS THAT MEDIUM WEAR :
MASTER CYLINDER. The hydraulic part that wears the most after the rear wheel
cylinders. 15 years is WAY too long to run one.
ONE - brake shoe and brake pad life are completely determined by where and
how the vehicle is driven. If all it ever does is cruise interstates, and
stop gently, almost no wear occurs. Mountainous driving, or steep street
driving as in San Francisco say - that just eats up friction material
Automatic Transmission vans and cars wear out the friction material,
generally speaking, a bit faster than manual trans vehicle. In both types,
down shifting helps.
TWO - DRUMS AND DISCS These don't have to wear much, unless you drive the
hell out of your brakes. If you smell 'burning brake pad material, like you
do off big trucks coming down big descents - that's pushing the brakes too
hard. If pedal effort goes up at the same time - 'break fade' you are REALLY
pushing it too hard.
You can actually get into a situation - say long high speed descent, like
going 60 a lot, using the brakes a lot, where the fad can get so bad.....the
brake fluid can boil at the caliper pistons - you can get into a situation
where you are unable to control the speed of the vehicle in a descent.
That's pretty extreme, but lot of weight in the vehicle.........and huge
descent like coming down Pikes Peak in Colorado - you can over-do what the
brakes are capable. By modern standards, vanagon brakes are marginally
adequate.
The discs don't usually wear that much. Normal repair when replacing pads is
to turn (re-surface ) the discs or replace them. They can only be turned
down so far. New ones aren't that expensive. Need to make sure the front
wheel bearings ( 2WD ) are adjusted and lubed enough.
Type of pad matters. I go with 'repco deluxe' and have for years. You want
the best combo of stopping power, quietness, and life. I'm tempted to try
some high performance pads on my 85 Weekender to get a bit better pedal
feel, but the MC isn't that great on that van anyway, so I'd do that first.
It's an automatic too, so brakes need to be top notch, as there is more
stress on them with an automatic.
There are tricks to breaking in new pads and discs - use them medium gently
to just a bit medium hard for the first few hundred miles. Both excessive
light use or very hard use during the fist few hundred miles is not right.
Always put 'disc brake quiet' a spray on or brush on vinyl like coating on
the back of brake pads. Use shims if they are fitted.
Super lightly lube the edges of pads so they can slide- copper anti-seize
compound. On brakes with a one piston sliding caliper, make SURE the slide
pins and bushings are smooth, move nicely, and I put a tiny dab of copper
anti-seize there as a lube. That is slide nicely is critical.
If dong 'PADS ONLY' on front discs, or as I'll sneakily do on my own van,
new front pads and change the brake fluid to each wheel -
NEW PADS on used discs - you get what you get. No promises of any kind.
If it squeals, or pedal pulsation develops, it's new pads and turn or
replace the discs, and if the pads are 3 days old, and it's not working
right, don't re-sue them. New Pads and turned or new discs is the only
viable repair.
Yet sometimes you can get away with putting new pads on good used discs -
but it's a plane gamble. No complaining if it doesn't' work out. Always
change the brake fluid to any brake you work on, period. Just flush some new
in.
What is more common in discs is glazing and squealing during stops. Or
getting out of true.
Never operate your van with excessive light braking only !
Always, exercise them to about 70 % effort, a couple times a week. Do it in
a safe place. This reduces the tendency toward squealing quite a bit.
Discs get out of true too- not even.
And pedal pulsation should be dealt with soon. It trashes up the suspension
if there is pedal pulsation and uneven braking on one wheel.
REAR DRUMS - the last darn well normally ! the last forever for me. Having
them turned or replaced for a 'full rear brake job' is best.
Rear shoes - depends no how hard you use the brakes. Normally they last
quite well. They tend to wear all at one end and not the other. The
self-adjuster doesn't always keep them as far out to the drum as ideal.
Emptying out the brake dust and tweaking the adjuster up a click or two, and
making sure the rear wheel cylinders are not leaking is a normal part of 'A
Service' to me.
THINGS THAT DON'T WEAR MUCH TO ME :
Parking brake cables - depends on environment, in a dry climate, they last
indefinitely. I have 4 good used ones I'm looking to use somewhere. If you
live in rust, whole other story.
And some people JERK HARD on the parking brake handle every time they park
the van. DON'T DO THAT. Put it on firmly if you need to, like on a slope.
For normal level parking, leave it in 2nd if manual trans, parking brake on
lightly. Use park with an automatic. No need to use the parking brake unless
it's a good slope. Or put in on 'some.'
And of course.......if no one lubes the parking brake mechanism, ever, don't
expect it to not wear. SOMEBODY has to lube it every now and then. Don't
think shops will.
Regarding jerking on the parking brake and things like that.
There are many people that are really rough and clumsy on their cars.
Jerking the shift lever, crunching sifts, driving too hard cold, jerking the
steering wheel, driving the snot out of the brakes , etc. AND THEY HAVE NO
IDEA THEY ARE DOING THIS.
I'm serious - I've seen people that will rip the shift lever out in a few
years, and they thought they were driving normally.
I've seen people that short shift every gear shift , and immediately floor
it and lug the hell out of the engine EVERY SHIFT ! Pounds out the rings
grooves of the pistons, and is rougher on the trans.
You should drive you van like making love to a woman - subtle artfulness
and finesse. And occasional intensity at appropriate times and levels.
You can drive hard and fast and still be easy on the equipment too.
BRAKE HOSES - I don't find they wear much ( in western climate ) but the
outer covers crack. They can clog up inside too, and fail to release
pressure. They should really be replaced about every 15 years max.
Of course ! - any brake hose that's 25 years old would love to be replaced.
Obviously.
BOOSTER - they seem to last forever mostly , but if money was no object,
every 10 to 15 years max.
I had a Honda Dealer charge a customer about 1,000 dollars for a new MC on a
5 year old Honda. I called them, they said, yeah if brake fluid gets into
the Booster, you have to replace it.
FRONT CALIPERS.
What they mainly suffer from is sticking pistons.
It's even possible to 'exercise the pistons' by using the brake pedal to
push one out a bit ( pads out ) then pry it back with a lever.
The Standard Repair for any caliper with sticky or stuck piston, or any
leaks ( rare though I my experience ) is a new Rbuilt Caliper.
It IS Standard Practice to do both sides if doing one side.
In everything, pads, calipers, discs, shoes, drums, etc.
BREAKE PRESSURE LIMITING VALVE,
Haven't seen a problem with them, though obviously, 25 + years of yuck in
there .......they can't last forever. I have never replaced one though.
That's it for now.
I'll probably think of more.
Thanks for the opportunity.
Scott
www.turbovans.com,
and that other part of my signature above.
