Master Cylinder - K10 to K20 conversion

[Mattchu60]

Hey there folks. Couple years ago I put 3/4 ton axles under my K10. When I did that I reused the 1/2 ton brake calipers on the front. In a few weeks I'm going to go ahead and replace those with the 3/4 ton calipers and put new brake hoses on the front as well.

My question - I know the 3/4 ton has a different master cylinder. I'd like to upgrade to the larger one as part of this process. Anyone know if I can bolt it up to the current K10 Booster, or does that need to be replaced as well? I know very little about Brake Boosters, so hoping someone else can tell me if this is a good/bad idea.

Thanks!

 

[bucket]

IMHO, just leave it alone if it doesn't need replaced. The K10 cylinder just gives a little softer feel with a little more travel, which is kinda nice in an emergency stop. It's only squishy feeling if you let the rear brakes go too long without adjusting them. The K20 cylinder isn't so sensitive to rear brake adjustment.

 

[MadOgre]

Upgrade to hydro boost and you'll have no issues any which way

 

[squaredeal91]

@bucket I'm in a similar situation. Planning to change front to 8 lug outers and to full floater rear in the future and I ordered a replacement K10 master. Boltd up good but I noticed that they differ a little bit. The reservoirs are opposite in size and the line sizes are the same but in opposite places. Question : am I correct to assume to simply just cross the lines because front and rear pistons are opposite? Or: do I need to change the line ends to fit?

 

[bucket]

@bucket I'm in a similar situation. Planning to change front to 8 lug outers and to full floater rear in the future and I ordered a replacement K10 master. Boltd up good but I noticed that they differ a little bit. The reservoirs are opposite in size and the line sizes are the same but in opposite places. Question : am I correct to assume to simply just cross the lines because front and rear pistons are opposite? Or: do I need to change the line ends to fit?

From what I remember based on all current and previous trucks, just swap the lines. Sometimes GM put the front brake reservoir towards the front, but sometimes they put it toward the rear.

 

[bucket]

@bucket I'm in a similar situation. Planning to change front to 8 lug outers and to full floater rear in the future and I ordered a replacement K10 master. Boltd up good but I noticed that they differ a little bit. The reservoirs are opposite in size and the line sizes are the same but in opposite places. Question : am I correct to assume to simply just cross the lines because front and rear pistons are opposite? Or: do I need to change the line ends to fit?

Did you get a master for a different year truck than what you have?

 

[squaredeal91]

Did you get a master for a different year truck than what you have?

Ordered master for same year only K20 not k10

 

[squaredeal91]

Comparison

 

[bucket]

Oh ok, I got ya now. I was under the impression that you were sticking with a K10 master.

But yeah, see how the sizes of the reservoirs are swapped? That means you just swap the lines. The larger one is for disc brakes.