  We present the results of a timing analysis undertaken with the goal of
obtaining an improved mass measurement of the recycled pulsar J2045+3633. Using
regular high-cadence observations with the Effelsberg, Nan\c{c}ay, and Lovell
radio telescopes, together with targeted campaigns with the Arecibo Telescope
and Effelsberg, we have assembled a 6-yr timing data set for this pulsar. We
measure highly significant values for the proper motion and the related rate of
change of orbital semi-major axis ($\dot{x}$), and have obtained high precision
values of the rate of advance of periastron time ($\dot{\omega}$), and two of
the Shapiro delay parameters ($h_{3}$ and $\varsigma$). This has allowed us to
improve the measurements of the pulsar and companion masses by an order of
magnitude, yielding (with $1\sigma$ uncertainties)
$1.251^{+0.021}_{-0.021}\,\text{M}_{\odot}$ for PSR J2045+3633, and
$0.873^{+0.016}_{-0.014}\,\text{M}_{\odot}$ for its white dwarf companion, and
has allowed us to place improved constraints on the geometrical orientation of
the binary system. Using our measurements of the binary component masses and
the orbital size, we consider possible evolutionary scenarios for the system.
