CALL911

iTrader: (17)

Which is the best GM Master cylinder to upgrade to on my 98 Formula? I am new to the LS1 world and I don't know what will fit, and or what would be best. Will a Z06, or LS6 master cylinder work?

brad8266

iTrader: (23)

Just go to the Gm dealer and ask for a master cylinder for your car, they have all been updated and they will give you the updated one.

CALL911

iTrader: (17)

I know I can just upgrade to the newer LS1 master cylinders. That wasn't exactly what I was asking. I wanted to know which one I should upgrade to? Which is the best for the money?

brad8266

iTrader: (23)

All of the ones from GM are the same i believe. They are all the same so it doesnt matter is you ask for one from a z06, 02 camaro, or 05 GTO, youre gonna get the same one either way. When they come up with a new one all the old model cars masters are replaced with the newest master out.

CALL911

iTrader: (17)

I have found that Mcloud offers an adjustable master cylinder for around $375 most places.

I also found that Ram makes an upgraded master cylinder as well for only around $175.

Are there any others? Will the Ram master cylinder do the job even though it costs less than half of the Mcloud?

brad8266

iTrader: (23)

What clutch are you using? The RAM is a good piece and there are some complaints about the McLeod. I have a McLeod and it has been working fine.

CALL911

iTrader: (17)

Well I just got the car a week ago, and the guy I bought it off of had it for 3 years and only put 7,000 miles on it. Long story short here, I'm not sure what clutch is in it. If I were to guess, I would say the stock one. It is a bone stock car, and it has 88,200 miles on it. The clutch seems to work fine (no slipping that I have noticed). The issue seems to be more of grinding gears inconsistantly when trying to shift. This leads me to believe it is the master cylinder.

I can install a Mcloud, or a Ram master cylinder to the stock clutch can't I? I also have heard I need to do the drill upgrade.

brad8266

iTrader: (23)

Try the drill mod first, that seems to solve a lot of grinding problems, also replace the hydro fluid and bleed the lines really good.

badpewter-z

iTrader: (4)

12570277 is the GM master you want. the vettes are different and will not work in an fbody. also once you get it do the drill mod as the new unit still has the restriction in it

unless you need the adjustability theres no reason to run an aftermarket master

brad8266

iTrader: (23)

I guess I was wrong about the same thing.

CALL911

iTrader: (17)

So are you saying the new 01, and 02 master cylinders are just as good as the Ram aftermarket one?

Also, I have read a little on the drill mod. How hard is it to do?

brad8266

iTrader: (23)

The RAM is better in the fact that its adjustable, you can adjust the clutch engagement points.

To do the drill mod when you replace the master just remove the braided line from it and drill out the little restrictor plate that is inside of the line, its very easy. That was the first mod i did when i bought my car. Well worth it too, it stopped my high rpm grinding while shifting.

badpewter-z

iTrader: (4)

not needed unless you need to have the adjustability thats the only advantage. might give you a stiffer pedal too?

Drill mod isnt that bad to do espically if its not even in the car yet

CALL911

iTrader: (17)

My car seems 100% stock down to the factory paper air filter and the factory skip shift. I would imagine that the drill mod has not been done either.

I know the Ram master cylinder costs around $175 or so. How much does the newer 01, 02 GM one cost?

badpewter-z

iTrader: (4)

150ish for a gm one

2QUIK4U

iTrader: (7)

I would just replace it with a GM one. Definately do the drill mod. I just replaced mine at the same time that I put in a new clutch. It made a big difference in high RPM shifting. My old master cylinder only had 50k on it and it was toast. It also depends on what clutch you are using. I had bought the Mcleod and installed it with the stock clutch and it worked ok. No better than the stock one and then I got a Textralia clutch which is supposed to be used with stock hydraulics so I had to switch back to a GM master cylinder.

CALL911

iTrader: (17)

Thanks for the info fellas. What about the slave cylinder though? Is this a common thing to go bad in a 98 as well? Should I also just upgrade it to a 01-02?

badpewter-z

iTrader: (4)

15046288 about 140ish for the GM slave and i would defiently cahnge that while your in there

A-Dub

iTrader: (6)

Am I the only one thats thinks the master cylinder won't solve your problems? If your only symptom is grinding gears when shifting, then I would bet your synchros are wearing out. They will cause inconsistent grinding until they get really worn.

CALL911

iTrader: (17)

If it were the syncros, it would more than likely do this at a high RPM shift in a certain gear or two, and possibly even pop the car out of gear as well, not to mention it would happen as well when I down shift. Non of these symtoms seem to fit this description.

The car has the grinding issues at low RPM shifts, it holds it in gear when it does go into gear, the grinding has been found in almost all the gears (not just one particular one or two) and it has never done it on a down shift. This just does not seem like the syncros to me. Especially given that it is a fact that the 98-00 year LS1's had several problems with their slave and master cylinders. Enough were they changed the design for the last two year models.