Tips on Buying Cars: 1998 Transport trade-in, head gasket leak, group power


Question
 I was negotiating to purchase a used 2005 Montana with 14K miles; a previous rental, last weekend.  Asking price was 19,995. My trade-in is a 1998 Transport with 74K. It is a great running van that recently had the water pump replaced.  We were between $13,500-13,800 in negotiations and I was told that the Wholesaler had to look at the van again.  
 When the guys came back I was told that my head gasket was leaking/bad and the job to fix it would cost the dealer $600, so the deal was off! Their indicator was low Dex-cool.
 What do you think happened?  Was I negotiating too aggressively and they wanted an out?
 Where can I get information on TSB's for my vechile with out having to pay for them? I know that their at least two that indicate coolant and head gasket leak.

Thanks for your time.

Answer
Hi Chris
I really like to help you on this one...here are a few answers i need from you...
I ask in every Q  to include postal or Zip as that gives me idea what vehicles are selling for in your area...guess you missed my request...
What model Montana...
short wheel base or LWB...
power group...
power sliding door...
leather...
DVD ...
On another note it must be a tight deal for the dealer to let you walk out with the diff being $600. and i assume thats where it stands now ?
Explain TSB's ?

Fill me more info
  Ray