DIY - Stock Raptor 2.5 Shock Rebuild.

[m3dragon]

We re missing a few images and detailed measurements. Adding these after 9/6

Step 33 would be where you pull the bypass piston up to the set point. I believe was 4 inch depth but we did not "official" measure. We used a zip tie and marked the depth. I will measure the marks and add to Step 33.

 

[seapong]

Great write up. The only thing I didn't see you comment on is the dividing piston depth(or as its was call in the write up "by-pass valve"). There should be a measurement from the open end of the reservoir to the dividing piston. This should be set and then tighten seal head at the shaft.
Thanks to the guys putting this DIY together.

Good point! A couple things to mention regarding that:

1. Since fluid is uncompressible, the amount of fluid that drains out, must be the amount of fluid that goes in.
2. Gauging purely on bypass diving piston (air+fluid separation point) is not necessarily a good way to judge the amount of fluid to put back in. Reasoning is as such: the piston may have shifted and caused a vacuum chamber to manifest in the fluid section. This will give you a "false" indication that more fluid exists. If you fill with too much fluid, you end up not being able to fill the air chamber with enough volume (not pressure) of air.

We have made this mistake already, and the symptom is: the shaft will not return to full extension as quick (since too much fluid = too little air volume, even though it is at 240psi = no enough force to excrete the shaft displacement)
____

Then we come to the question of, how to bleed air if: the dividing piston is bottomed out and there is still an air pocket below the dust wiper cap (no fluid is bleeding out)? If this is the scenario, something is wrong.

Check the following steps again:
1. When you are inserting the shaft assembly back into the fluid filled shock tube. The shaft must be in full extension (out-most position). This way you are minimizing the fluid displacement the shaft itself imposes.
2. The dividing piston should not already be at the bottom most position. You should use the piston as a syringe to suck a small amount of fluid to the bypass to make room for the shaft assembly insertion without overflowing. Once shaft/dust wiper assembly is inserted and fully tightened, press down on the dividing piston to bleed.
3. If you put the same amount of fluid in that came out, there should be minimal amount of fluid to bleed out (mostly air).

 

[M3toSVT]

Just what I was looking for. I just need to finish my headlight retrofit before I tackle another project. Great Job!

 

[Chris Crampton]

Good point! A couple things to mention regarding that:

1. Since fluid is uncompressible, the amount of fluid that drains out, must be the amount of fluid that goes in.
2. Gauging purely on bypass diving piston (air+fluid separation point) is not necessarily a good way to judge the amount of fluid to put back in. Reasoning is as such: the piston may have shifted and caused a vacuum chamber to manifest in the fluid section. This will give you a "false" indication that more fluid exists. If you fill with too much fluid, you end up not being able to fill the air chamber with enough volume (not pressure) of air.

We have made this mistake already, and the symptom is: the shaft will not return to full extension as quick (since too much fluid = too little air volume, even though it is at 240psi = no enough force to excrete the shaft displacement)
____

Then we come to the question of, how to bleed air if: the dividing piston is bottomed out and there is still an air pocket below the dust wiper cap (no fluid is bleeding out)? If this is the scenario, something is wrong.

Check the following steps again:
1. When you are inserting the shaft assembly back into the fluid filled shock tube. The shaft must be in full extension (out-most position). This way you are minimizing the fluid displacement the shaft itself imposes.
2. The dividing piston should not already be at the bottom most position. You should use the piston as a syringe to suck a small amount of fluid to the bypass to make room for the shaft assembly insertion without overflowing. Once shaft/dust wiper assembly is inserted and fully tightened, press down on the dividing piston to bleed.
3. If you put the same amount of fluid in that came out, there should be minimal amount of fluid to bleed out (mostly air).

Got it, I understand how your setting the dividing piston now. That would work no problem.

The reason a asked is I rebuild/tune the shocks on our TT & prerunners and assembly is a little different. Just making sure I didn't miss something.

 

[m3dragon]

Chris, These are not as complex as Pre-Runner shocks. As they aware a more mass produced unit things looked to be simplified. The main shock caps are the same units for example.

When it comes time to rebuild the 3.0 and 3.5's I run, we will do another write up with how to set those.

 

[Aussiesvt]

Looking forward to meeting up with you blokes.

Nothing like staring at a motor and talking shit to make friends.

 

[ntm]

Chris, These are not as complex as Pre-Runner shocks. As they aware a more mass produced unit things looked to be simplified. The main shock caps are the same units for example.

When it comes time to rebuild the 3.0 and 3.5's I run, we will do another write up with how to set those.

Actually they are more complex in a sense, and a royal pain to set the ifp depth and bleed (properly) compared to an external bypass, or even the 3.0 internal bypasses.

 

[m3dragon]

Do you mean the IFP for the fronts or the bypass body?

 

[ntm]

The fronts mostly.
But the typical external bypass has a lot less seals than the rears too.
Kind of off topic, but something I've also noticed with the internal bypasses is that the inner sleeve is often a bit loose, you can see the wear marks from it shifting, and I believe this causes the clunking noise many complain about.

 

[m3dragon]

As Sea pointed out on Post 12, we are still dealing with the same amount of fluid volume.

When we built the shocks we set them as we took them apart. The front internal floating piston is easiest set if you set to the snap ring. Then set the piston rod to MAX extension.

Front build is missing a lot of pics which I forgot to take as we did the work DOH!!! I will get those next rebuilds and you can see how things were set.