seiko crystal repair

[peterstock]

I am not an experienced watch person  but I do need to replace the crystal on my Seiko (probably from the 1970s)
from which side do I approach this? from the back, the mechancal side? Or from the front (by.... what? prying off the bezel?)
are Seiko crystals standard? or how do I find the correct crystal for my watch.?
Peter

[bklake]

Congratulations, you picked one of the more complicated crystal swaps to start out.  I don't know the caliber and model number of your watch but both are on the case back.  It should be 4 letters and/or numbers - followed by 4 letters and/or numbers.  This information will allow us to provide more specific help.

Next is study time.  Find the Seiko Casing Guide online.  Somewhere else on the caseback will be some codes that indicate the case type.  The Casing Guide will give you the instructions for removing and replacing the crystal. 

You will need the caliber-model number to search a parts database for the correct crystal part number.  Julesborel and boley.de are two databases. 

I have a Seiko crystal die set as well as a generic crystal set.  The Seiko set is the only one that fit and worked on a similar generation watch as your watch. 

[mikepilk]

You can download the casing guides here

https://www.watchrepairtalk.com/topic/13897-seiko-casing-parts-guide/#comment-123917

[peterstock]

on the back, I am seeing :
883329 (which I expect is a serial number)
and 7853-8000

does that mean anything?

[bklake]

883329 is the serial number.  First digit is the year of the decade the watch was made, second digit is the month, 3-6 are the sequence in production.  7853 is the movement family,  -8000 is the case model.  I'm not entirely familiar with the 7853 but I think they are 1970's or 1980's production.  So, 1978 or 1988. and August. 

Here is a link to the julesborel parts database for your watch.  Not a lot of parts listed for this model.  They may have them in stock or it will give you a part number to start you on your journey to find the part.  http://cgi.julesborel.com/cgi-bin/matcgi2?ref=sek+cs%237853-8000&submit=Search

Seiko crystal and gasket part numbers give you a lot of information that could be helpful in finding a generic part that may fit.  The crystal part number for your watch is 300WB4GA00.  It is 30.0mm, W usually means water resist, B4 means something-maybe what it is made of, the last two numbers are usually a sequence number.  I can't find my crystal and gasket decoder right now but there is a Seiko document that decodes all of the information in the part number. 

Before you get all excited about dropping any 30mm crystal in, be warned that these older Seikos use a somewhat complicated arrangement and the bevel on the edge is critical for correct seating and sealing.