M1008 brake master cylinder

[porkysplace]

Its not that checked that New rotors from napa and Timken front bearings both sides when the rotors got done. it seems to only pulsate as I brake the more pressure I do on the brake pedal the worse it gets and as you slowing down almost to a stop its a forwards backwards movement like something is still grabbing the truck has always acted funny but it seems worse now.Could the rear proportioning valve be bad?


Btw Tie rods and Drag link are all new not even a year old

I wouldn't think a Caliper was hanging up again but I suppose anythings possible.

Is this the same truck ?
[h=1]Steering issues with m1008[/h]
Did you ever service the king pins ? you may want to do a search for "death wobble" .

 

[SouthernSteel]

Is this the same truck ?
Steering issues with m1008


Did you ever service the king pins ? you may want to do a search for "death wobble" .

Yes,Thats the same truck but all new frontend parts were done and I fixed a grease fitting and greased them.Im not sure that's the problem as its not constant and I was riding with a friend who found out first hand so I know that feeling I don't think that's it the wobble would be some what constant right I only feel the shake and pulsation when I try to brake hard I don't feel any other shake before I start slowing down.

 

[SouthernSteel]

*******************UPDATE Im at a loss for words as to what the deal is**************

Well Folks,Im at a loss for words or actions Still doing the same thing had the tires rebalanced Front only.Checked both hubs and all suspension even greased every grease fitting I could find.Took both tires and got them rebalanced even bled both front calipers got fluid at each one so neither caliper is sticking and the rotors aren't that old I bought them new from napa (Pressure washing the truck wheels and I know water got on the rotors that wouldnt warp them would it).Though the tire guy did point out I had flat spots in my tires so with all that's going on with the truck the shaking is probably all tire.So im not sure what the exact problem is I cant afford new tires at the moment so until I get new ones I cant tell whats wrong I have done all I can,I just wanted to say thanks for the Master cylinder info and for the suggestions.You folks have been a big help and Im greatful.

 

[cucvrus]

Okay here is how to read the TMs. This applies to all the MVs

1 - First you have to decide which of the vehicles you are working on. M1009, M1008, M1028, etc
2 - Then you have to lookup the UOC (Usable on Code) for that vehicle. The UOCs are listed at the beginning of the manuals
3 - Then you lookup the part for that UOC

Some parts are universal across the series and some are unique to the type of vehicle.

So for your M1008 the manual lists the UOC as 194

Looking at the parts diagram in the TM 9-2320-289-34P parts manual for the master cylinder we find the picture listed as Figure 117

It shows two M/Cs, part #30 and #34.

Scrolling down you will find an entry for part #34 and #30

#34 has a UOC of 209 - That is the M1009 blazer. It isn't the right one

#30 has a UOC for all the other trucks. This is the one you are looking for

The CageC( manufacturer) code is 14892 (which is General Motors). The GM part number is 2232073. The NSN is 2530-01-156-7016

Googleing the part number comes up with nothing. So we will have to look the NSN number up on www.partstarget.com

NSN 2520-01-156-7016 comes up with a few different part numbers

http://www.parttarget.com/2530-01-156-7016_2530011567016_2232073.html

14076814
2231925
2232073
2530011567016

Now looking at all the different parts sites for a 1984 K30 6.2L master cylinder they show a couple of different ones with a "stamp" on the bottom, a "#1605" and a "#1925"

Looking at those numbers and and the possible part numbers, I would say that the #1925 is the M/C you want

Of course YMMV

I
Imagine that. I found out I needed to know a code for the master cylinder when I went to NAPA. I never needed one at Autozone. I think all they ask was with DRW or SRW or hydro boost or not. But I see Easter Find m1008 will take a TAG 1925 if I am reading this correctly. I also wanted to ask. is DOT 5 a special Master Cylinder. I never used any special Master Cylinders in the past. I just retained nice CUCV master cylinder lids and put them on the rebuilt master cylinders since they had Dot 5 embossed on them.

 

[firefox]

Good question cucvrus. BTW you might want to edit your post and change the % to a 5
for the sake of the newbes. I am still in awe of the work you do!

 

[cucvrus]

I also wanted to ask. is DOT 5 a special Master Cylinder. I never used any special Master Cylinders in the past.

https://youtu.be/E8NniKYiy2I