A DIY rubber roof job is pretty harsh. You MAY get it done, proably not..

Go online and look for eterna bond brand tape. It comes in rolls up to 8"
wide. Camping World also carries it, and the caulk for the roof
penetrations. Read up on it and I bet you can fix your roof right pretty
easily.

vv

There are various patches and preparations specifically made to repair
rubber roofs. There are also coatings designed to seal and prolong the
life of a rubber roof which might work for you. Here's what I would do
in your situation (not knowing how to deal with a rubber roof):
1) Consult a few of the many online suppliers to get an idea as to
what is available for rubber roofs.
2) Go to the manufacturers' websites and read what they say.
3) Call the one or two that you find most promising and talk to their
customer service techs and see what they say.
4) talk to your local repair facility and see what they say.
5) take all of that together and make the choice that best suits your
needs.

As one who just finished refurbishing a roof (not rubber) I can speak
from a bit of experience. I spent 80 hours on it, and I could have
easily spent another 20-30 if I thought I could beat the weather. Did
I have a point..? Oh! The point is that redoing ANY roof can take a
lot of time and effort, and if not done right it can be wasted effort.
To see what results from a bad roof job, see chapter 7:
http://home.surewest.net/frcn/MotorHome/

With any roof job, preparation is the key, and that takes time and
effort to do right.

Good luck!

 From Randy & Val
1990 30' Rexhal Airex

My own efforts to stop leaks in my roof are three fold.  I had a low
spot that didn't run off, and after awhile dissolved the paint and roof
sealant, thus causing leaks.  I built a drain in the low area, with the
drain running inside the space in the ceiling, draining out the side of
the trailer at ceiling level.  This has worked great.  After several
years of trying roof sealant over roof sealant with no success at
stopping the leaks, this has been wonderful (knock on wood.) That small
amount of water that does not drain, dries off in a day and there is no
more standing water.  With this fix, I used refrigerator sealant to
build a few small levies on the room to guide the water to the drain
hole.  This allowed me to be leak free for over 16 months, except once
when the drain got plugged and I didn't discover it for a while.  So, I
went one more step.

A few months ago, I used a different roof sealant called "Through the
Roof".  More expensive, but it is a clear, tight seal.  I covered the
entire potential-leak area with it, then Third, I used two coats of
primer/sealant paint from Glidden.

The drain removes most water and the sealant and two coats of
primer/sealant keep things sealed enough for any small amounts of
standing water to dry off before it finds a "missed" spot.

Some may think this to be overkill, or the wrong products to use, but I
have had NOTHING BUT SUCCESS and am very glad I did it.

Jodie