Need help with what tap i need for gear box. asap

[montessadam88]

Im having issues getting my power steering line the pressure one to seal. I think the threads in the gear box need cleaned up. I need to know what size tap i need for the pressure line fitting in the gear box. Its the one that takes a 18mm wrench please help me out i need to get my truck back up cause my fiance needs her truck. Its an 98 silverado k1500

 

[badazzbulldog]

is the o ring on the line going into the steering box ok that can cause it to leak?

 

[skylark]

As I recall that is a special size that is specific to saginaw steering.

 

[montessadam88]

Yes i used the new one that came with it. I also tried a few different o rings cause i have an o ring kit. No luck. Its leaking out of the fitting from around the threads and at the top of the fitting where the line meets the fitting