5th Gen multi piston vs stock single caliper

Redster

OK tech/cost evaluation of the options for using a wilwood or similar caliper upgrade for the front discs. We all know that the multi piston has more stopping power but at what cost; as in what all must be done to accomodate the changeover. I am at that crossroad ... got new x-drilled slotted rotors and was going back stock caliper, but couldn't resist getting ECC advice before I act. Whatchya think? Cool

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the RED one
You can talk about it all you want .... but you will never really know 'til you go

MEvang · Posted: Mon Mar 10, 2008 7:44 pm Post subject:

Here are some things that most people won't consider. Wilwoods like most 4 piston calipers are fixed, therefore your brakes will be more sensitive to lateral runout then a single piston (floating caliper) general where a floating caliper can tolerant .006-.008 runout and fixed caliper (which utilizes a larger pad) will pulsate the pedal at as little as .004-.002 runout. Not so technical, simply you can get a pulsation much easier.
Another thing to consider is most Wilwood 4 piston calipers are not weather sealed. Meaning they have no real dust boots. This means they have a short life in rain snow and mud, so if it's an everyday driver consider this.
On the other hand the Delco Moraine single piston caliper is one of the best calipers ever made, second only to it's larger cousin used on older GM's and trucks for many years. These units are very durable, have a great dust seal and last a long, long time without trouble. You can't beat these units for reliability.
The only thing that can be troublesome is crosion on the exposed slide pins. But buy new ones and coat them with silicon brake grease and they won't be a problem.
But the best thing is, parts are cheap, plentiful, and you can buy them any were. One thing that will never happen with a Wilwood.
If you want more stopping power consider using the older larger Delco calipers. I believe there is a way to use older spindles and someone here has covered this here.
Mike
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"That the automobile has practically reached the limit of its development is suggested by the fact that during the past year no improvements of a radical nature have been introduced." (Scientific American January 2, 1909).

Redster · Posted: Sat Mar 15, 2008 9:34 am Post subject:

Mike,
Thanx for the great tech advice/info. This was exactly what I had hoped for in response (though more technically supported than anticipated). You are right, I had not considered the run-out consequences of the obviously tighter tolerences with multi-pistons. Since the 'mino' will be all new on the brakes (front and rear), I am not overly concerned about its ability to stop. It will be likely driven almost daily, thus the importance of durability and anti-pulsating effects. Again, you provided excellent feedback which will directly contibute to this build. Hail 2

Thanx,
Red
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the RED one
You can talk about it all you want .... but you will never really know 'til you go

MEvang · Posted: Wed Mar 19, 2008 6:18 am Post subject:

I just overhauled the brakes on my '86 and it simply got everything new or rebuilt. The only modification, if you can call it that is I substituted the rear drums for a set of aluminum fined drum I had stowed away. Rare thing they used on some '78 Monta Carlo's and 3rd Gen Camaro's.
Mike
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"That the automobile has practically reached the limit of its development is suggested by the fact that during the past year no improvements of a radical nature have been introduced." (Scientific American January 2, 1909).

Redster · Posted: Fri Mar 21, 2008 8:07 pm Post subject:

Mike,
I am thinking with a complete overhaul and going back stock, it will give you solid stopping power. I have seen alum. drums but wasn't sure whether they paid dividends or not. Unless I horse trade for a pair along the line, I plan to go back w/the orig. steel. That is of course unless I get some feedback that I am missing out some real economic performance. Let me know how they are working for you. Cool

_________________
the RED one
You can talk about it all you want .... but you will never really know 'til you go

amp88fan · Posted: Wed May 21, 2008 1:26 pm Post subject:

i recently aquired my 78' and plan on doin a full restoration on it, but want to drive and enjoy it while doing so....one of my first task is the brakes...i had looked at several diff kits to convert my rear drums to disc and upgrade the fronts to larger rotors and multi piston calipers,etc...but after seeing what this can cost i have came to the conclusions that..for one my budget wont allow it...and two...if i replace the brakes all the way around it..drums, rotors,calipers,hardware,new backing plates,master cyl,booster,and lines...all of witch is allways in stack at my local autozone...i will have less than 500.00 bucks in it all and i am confident that they will provide sufficant stopping power and i can prep and paint the parts before installing for a great looking setup!
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78' EL CAMINO SS(mine)

84' OLDS CUTLUSS CALAIS(the wifes)

MEvang · Posted: Wed May 21, 2008 9:01 pm Post subject:

Here's some advice. Power boosters rarely go bad. If it works let it alone. Same with the master cylinder, if it's not leaking from the rear seal, and if it appears to be the original leave it. If you can confirm it is remanufactured unit replace it with a new unit only. Rebuilt masters are a big waist of money, they rarely last long and are usually a time bomb waiting to go off.
Brake lines and hoses on older cars are of no value, replace them all. There is no reason to mess with them they are cheap, replacing them can save many headaches. Same with parking brake cables, the front rarely goes bad, but the rears are usually a lost cause.
You are right on the backing plates. GM in their infinite wisdom made these backing plates very thin as their vehicles were on a serious diet in 1978. These backing plates were known to wear through or rust out. Another item that got trimmed was the wheel cylinders, the bolts disappeared and a chip ring was used in a D shaped hole in the backing plate. These wheel cylinder were known to twist in the hole and blow out. A good replacement should come with a new clip and have a prongs cast into it to center it on the arbor and keep it from twisting.
Up front replace the wheel bearings. If they have over a 100K it's time for new ones. Rotors and drum can be reused as long as they are with in machine too specifications. But check the rotors careful sometimes on older cars the fins can rust away from the inside. So if they look real rusty you may be better off replacing.
Calipers are inexpensive remanufactured, but be careful. Cores are getting bad, look for bent ears (where the pins go through) bleeder repair kits, excessively rust pitted housings, and pistons that appear to have been sand blasts and painted. Reject them if you find any of this. Replace the slide pins. These are important and rusty ones don't work well. These cars came with metallic pads. Your better off with metallic then carbon fiber in most cases.
Finally use a good synthetic brake fluid. Do not use silicon fluids. The synthetics are far more superior.
Follow these steps and you'll save money and lots of aggravation.
Mike
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"That the automobile has practically reached the limit of its development is suggested by the fact that during the past year no improvements of a radical nature have been introduced." (Scientific American January 2, 1909).

amp88fan · Posted: Wed May 21, 2008 10:33 pm Post subject:

thanks for the detailed info on refurbishing the brakes....so i had planned to replace the m/c and booster....you say it should be fine?....and you mentioned some hassels....excactly what kind of hassles are we talkin here? to replace the m/c and booster,if i am replacing everything else anyway? i have worked on many brakes front and rear but have never swapped out a m/c or brake booster before....dont get me wrong i know you must bench bleed the m/c but what does it take to get the booster swapped out?
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78' EL CAMINO SS(mine)

84' OLDS CUTLUSS CALAIS(the wifes)

MEvang · Posted: Thu May 22, 2008 8:58 pm Post subject:

Not really any hassles replacing them, the problem comes with rebuilt units and this is what you are going to find. Many times they are not as good as a working original unit. If you want to replace the master cylinder, just make sure you get a new unit. Raybestos and Napa make good new unit but also make rebuilt's so make sure you specify new. Auto Zone likely only carry rebuilt's.
But my opinion is if the booster is working stay with the original, they don't wear out and rarely fail so I see no reason to replace it.
Mike
_________________
"That the automobile has practically reached the limit of its development is suggested by the fact that during the past year no improvements of a radical nature have been introduced." (Scientific American January 2, 1909).

amp88fan · Posted: Thu May 22, 2008 11:00 pm Post subject:

MEvang · Posted: Fri May 23, 2008 6:24 am Post subject:

You may find NOS parts but that might be a stretch. As I said aftermarket company like Raybestos do produce new master cylinders which are very reliable. Booster on the other hand are always rebuilds.
I have used Cardone a lot for rebuilt ABS parts. They also supply power brake boosters. I was always happy with their quality. But take note, many rebuilders sell booster with master cylinders. These masters are always cheap rebuilds. If you buy one like this just toss the master and get a new one.
Another alternative is to buy a good used booster and you can always upgrade to new model boosters that tend to give better braking.
While your checking salvage yards another upgrade you should consider is a swap to '80 up spindles. 1978 used a smaller outter wheel bearing and a one year off rotor. If you get spindle from a '80 up Malibu, Monta Carlos, El Camino or any other intermediate GM use will get the benefit of the better wheel bearings and a much more plentiful rotor which is likely cheaper to buy new.
Lastly if stuff is rusty the front rotor backing plates shields are still available from GM for about 20 bucks each. Part numbers 459757 SHLD ASM and 459758 SHLD ASSM.
Mike
_________________
"That the automobile has practically reached the limit of its development is suggested by the fact that during the past year no improvements of a radical nature have been introduced." (Scientific American January 2, 1909).

amp88fan · Posted: Fri May 23, 2008 9:25 am Post subject:

ok here is the new m/c i plan on getting....

http://www.autozone.com/R,APP15092/vehicleId,1301204/initialAction,partProductDetail/store,693/partType,00007/shopping/partProductDetail.htm

now my car has a duel diafram booster...can that be replaced by a single diafram for better clearance or must i go with the deul?.....

and if i get a rebuilt cardone booster with the new m/c...i should be ok?

http://www.autozone.com/N,14400143//shopping/partTypeResultSet.htm
_________________
78' EL CAMINO SS(mine)

84' OLDS CUTLUSS CALAIS(the wifes)

amp88fan · Posted: Fri May 23, 2008 10:27 am Post subject:

i would like to find a complete kit to replace my brakes....i would love to convert the rears to disc...i am on a budget of about 1200.00 but i cant find anyone who sells the complete set for my 78'
_________________
78' EL CAMINO SS(mine)

84' OLDS CUTLUSS CALAIS(the wifes)

amp88fan · Posted: Fri May 23, 2008 5:56 pm Post subject:

MEvang · Posted: Sat May 24, 2008 7:34 am Post subject:

The numbers and price I gave you are GM numbers, go to your local Chevy dealer and they can get them. Split rear backing plates were popular about 10 years ago but I have seen them around for a while. Domain or Motor Mite may have them. If you can't find them and need them IM me I have a pair.
IF your hot on rear disc brakes I recommend the late S10 brakes. Mater of fact I have a request in to my buddy that owns a salvage yard to be on the look out for a donor for me.
About your Auto Zone master cylinder Fenco is a Canadian company that claims to be an OEM supplier to Ford. I have no experience with their products so I can't recommend them. They may be good I just don't know.
Mike
_________________
"That the automobile has practically reached the limit of its development is suggested by the fact that during the past year no improvements of a radical nature have been introduced." (Scientific American January 2, 1909).